Labour and Delivery: An Updated Guide 9811961441, 9789811961441

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Labour and Delivery An Updated Guide Ruchika Garg Editor

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Labour and Delivery

Ruchika Garg Editor

Labour and Delivery An Updated Guide

Editor Ruchika Garg Department of Obstetrics and Gynecology Sarojini Naidu Medical College Agra, Uttar Pradesh, India

ISBN 978-981-19-6144-1    ISBN 978-981-19-6145-8 (eBook) https://doi.org/10.1007/978-981-19-6145-8 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

Foreword 1

The book Labour and Delivery by Springer Nature is an easy-to-use, ready reference guide. All the chapters reflect current evidence to support management strategies. This book will help postgraduate students and practitioners as it fuels an interest and thirst for knowledge in them as obstetrics needs clear understanding and practical tips. I must congratulate the authors and editor for bringing such an extensive book covering all aspects of labour and delivery with recent recommendations and literature supporting it. It will also invoke an attitude of research as many latest studies have been quoted. It is a must-read guide for midwives, obstetricians, those pursuing postgraduate degrees in Obstetrics and Gynaecology, trainees preparing for MRCOG Part 2, DNB part 2, NEET PG, etc Prof Prashant Gupta, Dean, SN Medical College,Agra. I am happy to recommend this book for inclusion in all libraries, and currently this book is one of the best and latest books on Labour and Delivery. Readers will definitely be benefitted from this book and will not have to search the internet or any other books for any query related to Labour and Delivery. The Editor Ruchika Garg and authors have long teaching experience and I am sure this book will invoke more quest for reading and clear the concepts of readers. Agra, India

Narendra Malhotra

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Foreword 2

The book Labour and Delivery by Springer covers all aspects of Labour which obstetricians deal with in everyday life. The book covers guidelines of various international organisations and latest information on labour and delivery which is the need of the hour. The book has multiple illustrations, tables and is very precise to grab important information. All the authors have penned down their vast experience in contributing for the book, and the editor must be congratulated for bringing this book as this is the most recent book focusing on the latest evidence-based management of labour and delivery and no topic has been left. This book is a must in the armamentarium of all undergraduate and postgraduate students, those pursuing MRCOG Part2, DNB and NEET PG Entrance test. PRESIDENT FOGSI Mumbai, India

Jaydeep Tank

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Foreword 3

It is my pleasure to write a foreword for Labour and Delivery: An Updated Guide. This book covers all aspects of labour management to help obstetricians manage labouring women in all conditions. The authors and Editor Ruchika Garg have added all the latest development and evidence-based research to the book. Various scientific studies available on all topics have been added in the chapters. This book is authored by a team of internationally recognised experts. It presents comprehensive and latest knowledge along with basic facts. Topics are very easy to learn and grasp. The book will cater to the reading quest of undergraduates, postgraduate students and practising consultants. SN Medical College Agra, India

Prashant Gupta

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Preface

Even in the era of online reading in my opinion books should be the best friend of every clinician as they are handy and ready to fill the gaps in our knowledge. This book will help postgraduate students pursuing obstetrics, midwives and busy practitioners develop interest in obstetrics and will definitely hone their clinical skills. We have focused on a comprehensive survey of current literature to bring out the latest evidence-based piece of knowledge. Crystal clear clinical paradigms have been discussed to keep obstetricians abreast of the latest guidelines. All topics related to labour starting from basics have been covered. A lot has changed in emergency obstetrics from guidelines for caesarean hysterectomy to labour analgesia. All have been discussed at length. This book has covered all topics in a simple easy-to-understand language and at length, so that readers will not have to search any other literature for enhancing their knowledge. Our book is a quick and easy reference guide for teachers, academicians, researchers and practicing clinicians. All the contributors have provided latest information which will definitely improve maternal and neonatal outcome. Agra, Uttar Pradesh, India

Ruchika Garg

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Acknowledgments

I am extremely indebted to my husband Prof Prabhat Agrawal who has always given me the right direction and encouragement and my kids Palakshi and Pratham for their love and support. I would like to sincerely thank Dean SN Medical college Prof Prashant Gupta for encouraging me at every step. I sincerely thank Prof Richa Singh for her valuable contribution to the book. I am grateful to all the contributors as they have curated this book with evidence, experience and expertise. I am hearty grateful to team at Springer Nature Publishers Jagjeet Kaur Saini, Uma Maheshwari S, Ellen Seo and Shalini Kameshwaran for bringing out this book flawlessly.

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Contents

 hysiology of Labour����������������������������������������������������������������������������������������   1 P Sajala Vimalraj and Bindu Vijaykumar  echanism of Labour����������������������������������������������������������������������������������������  17 M Vinayachandran S. and Sajala Vimalraj Cephalopelvic Disproportion����������������������������������������������������������������������������  35 Priyankur Roy, Roli Parvat, and Athulya Shajan Part I Abnormal Presentation  ccipito Posterior Position��������������������������������������������������������������������������������  57 O G. S. Jyothi, Cipta Pramana, Ariawan Soejoenoes, and Radhika Chetan Breech Presentation ������������������������������������������������������������������������������������������  75 Astha Lalwani, Neharika Malhotra, and B. Aruna Suman Face Presentation ����������������������������������������������������������������������������������������������  99 Shubhra Agarwal and Suchitra Pandit Transverse Lie���������������������������������������������������������������������������������������������������� 107 Jayashree V. Kanavi and Rajshree Katke Brow Presentation���������������������������������������������������������������������������������������������� 115 Syeda Batool Mazhar and Zahra Ahmed Muslim  mbilical Cord Prolapse and Cord Abnormalities���������������������������������������� 121 U Soniya Dhiman, Rishu Goel, and Priya Thakur Part II Antenatal Care Newer Concept of Antenatal Care and Antenatal Examination/Assessment���������������������������������������������������������������������������������� 135 Pramila D’Souza, Reena Wilma Frank, Joylene Diana D’Almeida, and Shashi Kabra Maheshwari

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Contents

Part III Labour  irst Stage of Labor ������������������������������������������������������������������������������������������ 161 F Sarita Agrawal, Sarita Rajbhar, and Jyotshna Kashibhatla  econd Stage of Labor: Current Trends in Management������������������������������ 179 S Pavika Lal, Igor V. Lakhno, and Garima Gupta  hird Stage of Labour �������������������������������������������������������������������������������������� 189 T Deepa Chaudhary and Tshering Wangden  artogram: What Is New���������������������������������������������������������������������������������� 205 P Shelly Agarwal, Shehla Jamal, and Dib Datta Abnormal Labour���������������������������������������������������������������������������������������������� 215 Mini Sood and Pinkey Lakra Abnormal Uterine Action���������������������������������������������������������������������������������� 219 Munjal Pandya and Janki Pandya Part IV Third Stage Abnormalities Postpartum Hemorrhage���������������������������������������������������������������������������������� 227 Krupa Shah, Rajshree D. Katke, and Sakina Y. Radiowala Uterine Inversion������������������������������������������������������������������������������������������������ 259 Zinnat Nasreen Ara and Divya Yadav Sharma Part V Placental Abnormalities Retained Placenta���������������������������������������������������������������������������������������������� 271 Archana Kumari and Ritu Raj Placenta Accreta Spectrum ������������������������������������������������������������������������������ 281 Sruthi Bhaskaran and A. G. Radhika Part VI Higher Birth Order Pregnancies Multifoetal Pregnancy �������������������������������������������������������������������������������������� 305 Suparna Grover Monochorionic Twin Pregnancy���������������������������������������������������������������������� 321 Ganesh Dangal and Nishma Bajracharya Part VII Complications of Labour Shoulder Dystocia���������������������������������������������������������������������������������������������� 335 Poonam Yadav, Abhilasha Yadav, and Richa Singh Obstructed Labour�������������������������������������������������������������������������������������������� 345 Vijayata Sangwan and Pinkey Lakra

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 pisiotomy: Recent Recommendations������������������������������������������������������������ 349 E Sadaqat Jabeen and Munjal Pandya  hird and Fourth Degree Perineal Tears: Surgical Aspects�������������������������� 359 T Avantika Gupta and Haritha Sagili Prolonged Pregnancy���������������������������������������������������������������������������������������� 373 P. Pallavee and Ashwini Vishalakshi L Preterm Labour������������������������������������������������������������������������������������������������� 387 Savita Somalwar, Anuja Bhalerao, and Nikita Vijay  reterm Premature Rupture of Membranes �������������������������������������������������� 405 P Navdeep Kaur Ghuman and Pratibha Singh Cervical Insufficiency���������������������������������������������������������������������������������������� 419 Neha Agarwal, Saroj Singh, and Shikha Singh Vulvar Hematomas�������������������������������������������������������������������������������������������� 435 Richa Sharma and Bharti Singh  mniotic Fluid Embolism �������������������������������������������������������������������������������� 447 A Ma Saung Oo and Mya Mya Thwin Postpartum Collapse������������������������������������������������������������������������������������������ 455 Ritu Sharma and Neha Mishra Part VIII Instrumental Delivery Ventouse Delivery���������������������������������������������������������������������������������������������� 479 J. C. Malavika and Neharika Malhotra  bstetrics Forceps Delivery������������������������������������������������������������������������������ 495 O Apurba Kumar Dutta and Priyanka Rai Part IX Fetal Monitoring  ntepartum Assessment of Fetal Health���������������������������������������������������������� 515 A Suman Chaudhary and Deepa Chaudhary I ntrapartum Fetal Monitoring�������������������������������������������������������������������������� 529 Ruchika Garg, Priyankur Roy, Athulya Shajan, and Monika Singh Part X Cesarean Section  trategies for Cesarean Section Rate Reduction�������������������������������������������� 549 S Shikha Seth  ifficult Scenarios in Cesarean Section ���������������������������������������������������������� 563 D D. Kiranmai Devineni, Medarametla Vijayshree, Priya Thakur, and S. Shanthakumari

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 aginal Birth After Cesarean (VBAC) ������������������������������������������������������������ 573 V Kiran Trivedi Caesarean Myomectomy ���������������������������������������������������������������������������������� 583 Anuja Bhalerao, Savita Somalwar, Krutika Bhalerao, and Shaily Agarwal Caesarean Hysterectomy���������������������������������������������������������������������������������� 589 Anuja Bhalerao and Krutika Bhalerao Part XI Management of Labour I nduction of Labour������������������������������������������������������������������������������������������ 599 Dalia Rafat and Farah Azhar  luid Therapy in Labor������������������������������������������������������������������������������������ 621 F Gehanath Baral and Ekika Singh  pdates and Advances in Labour Analgesia �������������������������������������������������� 633 U Amit Basu, Srabani Auddy Basu, Ipsita Chattopadhyay, and Urvashi  lood Transfusion in Obstetrics ���������������������������������������������������������������������� 651 B Pavika Lal and Ruchika Garg Part XII Puerperium Puerperium�������������������������������������������������������������������������������������������������������� 671 Lineo Matsela  omplications of Puerperium�������������������������������������������������������������������������� 687 C Sudhaa Sharma and Neha Mahajan

About the Editor

Ruchika  Garg  is an MD and Fellow of Indian College of Obstetricians & Gynaecologists. She is a member of the National Academy of Medical Sciences, FIAOG, FICMCH, and FMAS. She is a Professor at the Department of Obstetrics and Gynaecology, SN Medical College in Agra, India. She is Associate Editor of the Journal of Midlife Health (Pubmed) for the years 2022–2024 and of Scopus-indexed Journal of SAFOG (South Asian Federation of Obstetrics and Gynaecology) since 2013. She serves as peer reviewer for many international journals. Since 2013, she has been the Joint Editor of the Journal of SAFOMS (South Asian Federation of Menopause Societies). She is the Editor of the book Medical Disorders in Pregnancy, Obstetrics Update and editor and co-editor for several other books. She has authored and co-authored around 80 chapters in standard books. She is the recipient of Corion Award (both Senior and Junior category) for her research, Federation of Obstetric and Gynaecological Societies of India (FOGSI) Future Award, Sushma Swaraj Award, and many other awards. She has presented many papers and delivered several lectures nationally and internationally. She is an undergraduate and postgraduate medical teacher and examiner at various universities. Dr Ruchika has more than 160 scientific publications in peer-reviewed international journals with 250 citations.

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Physiology of Labour Sajala Vimalraj and Bindu Vijaykumar

1 Introduction Human gestation lasts for 40 weeks. During this, phases of uterine quiescence and cervical competence nurture the foetus. Near term, for reasons not entirely known, inhibitory effects of pregnancy are released. A series of biochemical changes in the uterus and cervix, mediated by paracrine and endocrine signals from the mother and foetus, culminate in the onset of labour—a diametrically opposite phase of uterine activity and cervical softening and dilatation, over hours, resulting finally in the expulsion of the foetus and afterbirth. Biochemical changes begin in the cervix, followed by uterine contractions, cervical dilatation and membrane rupture [1–3]. The onset of labour in humans is due to a release from uterine quiescence, rather than an active process involving sudden release of stimulatory factors. Whereas preterm labour appears to be the consequence of activation of labour due to infection, inflammation or other pathologic disorders, which short circuit or overwhelm the normal parturition cascade at term.

2 Overview A lot of work has been done on the physiology of human labour, but a lot of uncertainty remains. What is known, however, is that the maternal and foetal compartments, the sex steroids and prostaglandins (PG) all have a role to play.

S. Vimalraj Government Medical College, Kozhikode, Kerala, India B. Vijaykumar (*) Department of Obstetrics and Gynaecology, Government Medical College, Kozhikode, Kerala, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_1

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In the materno-foetal compartment, the uterine smooth muscles have various properties that help in carrying the pregnancy to term and then helping in expelling the mature foetus, as detailed below. The endometrium transforms into decidua, whose initial immunosuppressive effects maintain pregnancy; at term, activation of inflammatory signals and withdrawal of active immunosuppression contributes to parturition initiation. The cervix is a barrier to ascending infection and maintains cervical competence during much of early pregnancy, while concurrently allowing matrix changes that increase tissue compliance to enable effacement and dilatation later. The placenta and membranes are a key source of steroid hormones, growth factors and other mediators that maintain pregnancy by an immunological, metabolic and physiological shield, and, at term, aid transition to parturition initiation. The tensile strength of the amnion resists tearing and constitutes an avascular filter that protects from amniotic fluid constituents that can prematurely cause decidual or myometrial activation. The chorion has enzymes that activate uterotonins. Regarding the foetal role, it causes direct changes in the hormones with maturation, aiding parturition. The sex steroids, oestrogen and progesterone, are known to be important in pregnancy maintenance and parturition initiation in most species. In humans, however, both oestrogen and progesterone are very high, and possible subtle change in their ratio is what is important towards term, so that at least a ‘functional withdrawal’ of progesterone occurs.

2.1 Oestrogen The role of oestrogen is less well understood. It aids progesterone responsiveness to maintain quiescence in early pregnancy and at term, and aids processes that mediate uterine contractions and cervical ripening. The relative concentrations and activity of the nuclear receptor isoforms of both hormones oestrogen receptor (ER)-α, ER-β, progesterone receptor ((PR)-A and PR-B) may play a role in these differing actions. Plasma membrane-derived prostaglandin isomerases also have tissue-specific expression, inactivation etc. that modulate their activity, thus allowing them to contribute both to early myometrial relaxation and later, uterine contractions. Bioactive peptides and PG synthesised in the amnion also aid these functions and could be a major source of PG at term. In this chapter, we take a look at the phases of parturition and the physiological and biochemical processes that regulate it.

3 Phases of Parturition In the human species, the transformation in the uterine and cervical functions can be arbitrarily divided into four phases, as shown in Fig. 1. Phase I: Inhibition—uterine quiescence and cervical softening

Physiology of Labour

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Fig. 1  Phases of parturition

Phase 2: Activation phase (myometrial priming)—preparation for labour Phase 3: Stimulation—labour Phase 4: Involution—the puerperium

4 Phase 1 From the beginning of pregnancy till a few weeks prior to the onset of labour.

5 The Uterus During pregnancy, the uterus undergoes extensive changes in size and vascularity to accommodate the foetus, and in spite of the inherent tendency of the uterine muscle to contract, it remains unresponsive to natural stimuli, and yet it prepares for contractions at term! During this period of uterine quiescence, some low-intensity contractions occur and increase in frequency towards term, called Braxton-Hicks contractions; these may be perceived by the mother, but they do not cause cervical dilatation. This state of functional quiescence is a result of the action of inhibitors like: • • • • •

Progesterone Prostacyclin (prostaglandin I2) Relaxin Parathyroid hormone-related peptide Adrenomedullin

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• Vasoactive intestinal peptide • Nitric oxide • Calcitonin gene-related peptide

6 The Cervix The cervical consistency is like the nasal cartilage in the non-pregnant state that softens to attain the consistency of the lips of the oral cavity, with a great increase in tissue compliance due to changes in the extracellular matrix; yet it remains firm and unyielding till the changes of phase 2 set in [2, 3].

6.1 How Does This Softening Occur? Collagen, which is the main structural protein in the cervix, undergoes many changes which alter its strength and flexibility. Usually, stable collagen fibril formation requires cross-links between the collagen triple helices, mediated by cross-link formation enzymes lysyl hydroxylase and lysyl oxidase. Beginning in early pregnancy, there is a reduction in expression and activity of these enzymes, resulting in decrease in cross-links. There is also a reduced expression of matricellular proteins, which influences collagen structure and strength like Thrombospondin 2 and Tenascin C. Stromal hypertrophy, glandular hypertrophy and hyperplasia and the above structural changes in the extracellular matrix along with increased vascularity cause slow progressive softening of the cervix. Thus, in women with inherited defects in collagen and elastin synthesis or assembly, like Marfan syndrome or Ehlers-Danlos syndrome, there is a greater prevalence of cervical insufficiency. Thus, in phase 1, the uterus remains quiescent and the cervix softens, but retains its unyielding nature.

7 Phase 2 7.1 Myometrial Priming—Preparation for Labour The activation phase begins 6–8 weeks before term and ends with the onset of regular uterine contractions. In this section, we will be trying to answer why this happens, what decides the timing and what are the chemicals involved and the roles they play.

7.1.1 Why Does the Change Occur from Quiescence to Being Ready for Contractions? Progesterone withdrawal plays an important role, but we must realise that in humans, there is no actual fall in progesterone levels; it is more of a functional withdrawal.

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Here, the progesterone is no longer available to the myometrium, probably due to alteration in the progesterone receptors. Oestrogens, PG and other peptide hormones also play a role, most of which still await elucidation.

7.1.2 When Do These Changes Occur? Usually in the last 6–8 weeks of pregnancy. Any shift in this timeline will cause preterm labour or post-datism. 7.1.3 What Are the Changes That Occur? Changes in the myometrium—that prime the uterus to respond with contractions when exposed to uterotonic agents. Cervical ripening—an extensive remodelling of the cervix, which includes changes in the endocervical epithelium and cervical connective tissue changes. Figure 2 shows the mediators involved in phase 2. Let us take a look into these changes.

Fig. 2  Mediators in phase 2 of parturition

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8 Myometrial Changes 1. Alteration in the expression of key proteins that control contractility, i.e. the CAPs or the contraction-associated proteins, viz. (a) Oxytocin receptors—increases greatly, along with an increase in number and surface area of the gap junctions [1]. (b) Prostaglandin F (PGF) receptors. (c) Connexin-43—gap junction proteins. This increase in gap junctions between the myometrial cells permits electrical synchrony and thus, effective co-­ ordination of contractions. 2. Formation of the lower segment—it is not known why the lower segment forms towards term. It could be due to a differential expression of PG receptors in the lower segment or due to an expression gradient of oxytocin receptors (with more receptors in the fundus).

9 Cervical Ripening 1. Endocervical epithelium—proliferation of endothelial epithelial cells causes an increase in endocervical gland mass. Endocervical canal is lined by mucus-­ secreting columnar and stratified squamous epithelial cells which have antimicrobial properties and also probably regulate tissue hydration and maintenance of barrier function. 2. Cervical connective tissue [4–6]. (a) Collagen: Multiple molecules of triple alpha chain helices (procollagen) are held by cross-links to form fibrils (collagen). These fibrils are normally tightly packed in regular and organised manner, with the help of proteoglycans and matricellular proteins. During ripening, accumulation of poorly cross-linked fibrils and a reduced expression of matricellular proteins cause increased diameter of the fibrils and increased space between the fibrils, which leads to loss of tissue integrity and increased compliance. An increase in matrix metalloproteases may degrade collagen too, but this is not seen to be as important in humans compared to other species. In humans, it is more of a structural change than a degradation and loss. (b) Glycosaminoglycans: These are polysaccharide protein complexes, e.g. Hyaluron (HA), which may be of low or large molecular weight, depending on which the functions differ. Large-molecular-weight HA increases viscoelasticity and matrix disorganisation, while low-molecular-weight HA has pro-inflammatory properties. Hyaluronan synthase enzymes are seen to increase during ripening and hyaluronidase enzymes, which break down large- to low-molecular-weight HA, show increased activity near term. (c) Proteoglycans:

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Fig. 3  Changes in the collagen fibres in the cervix



These have a protein core with glycosaminoglycan chains, e.g. decorin, biglycan and fibromodulin. They influence the packing and ordering of collagen fibrils. Changes in their composition are thought to accompany cervical ripening at term. They are also expressed in foetal membranes and uterus and are thought to regulate foetal membrane tensile strength. (d) Inflammatory changes: An inflammatory process, wherein chemo-attractants increase inflammatory cells, which release proteases that degrade collagen and other matrix components, which was thought to be one of the mechanisms of ripening. However, further studies have not been able to substantiate this theory. Instead, it was found that the increase in pro-inflammatory and immunosuppressive activity is more in the postpartum phase of cervical remodelling and repair [7, 8]. Figure 3 depicts the changes in the collagen fibres in the cervix.

Cervical ripening thus takes place from 2 weeks to few days before labour in preparation for effacement and dilatation with uterine contractions in phase 3. Thus, our understanding of the changes in the cervix leading to ripening has helped us in clinical methods of induction of labour, but we have not been able to successfully prevent premature cervical ripening and preterm labour.

10 Physiological and Biochemical Processes Regulating Parturition The series of events at term, beginning with the removal of factors ensuring uterine quiescence and activation of factors promoting uterine contractions and cervical softening that takes place in phase 2 of labour, is known as the parturition cascade. It is a complex phenomenon involving the foetus, mother and placenta. In spite of vast amount of research it has not been possible to fully elucidate this exact mechanism of start of labour, but it is thought that the foetus–amniotic fluid– foetal membrane–decidua complex is a metabolically active unit that may transmit and respond to signals that initiate labour [8].

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11 Role of the Foetus Foetus has a definite role in the initiation of parturition. In phase 2, foetal hypothalamic-pituitary-adrenal axis is activated. There is an increase in the secretion of foetal corticotrophin releasing factors (CRH), which stimulates the foetal pituitary to secrete adrenocorticotropic hormone (ACTH), which will go and stimulate foetal adrenals, which in turn produces dehydroepiandostenedione (DHEAS). Placenta converts the foetal DHEAS to oestradiol, which stimulates the uterine contractions by binding with oestrogen receptors and thereby stimulating the production of PGF2α, oxytocin receptors, PG receptors and gap junctions. Foetal adrenals also produce cortisol, which can stimulate the production of PG and oxytocin from the placenta and can increase placental CRH, which occurs mainly in the third trimester. This placental CRH also may act on foetal pituitary and adrenals to produce ACTH and DHEAS, respectively [9, 10]. Prostaglandin synthesis occurs in the amnion, chorion and decidua from arachidonic acid, which is stored in the form of glycerophospholipids here, which in turn will increase the formation of gap junctions, cervical ripening and activation of contractions.

12 Role of Placenta Main function is exchange of nutrients and waste between mother and foetus. But it is a source of steroid hormones, growth factors and other mediators that can start the process of parturition. Amnion provides for the tensile strength to prevent membrane rupture. It is resistant to penetration by organisms and leucocytes. It also prevents foetal lung and skin secretions from reaching the maternal blood, hence the mother is protected from amniotic fluid embolism or premature activation of the parturition process. Chorion primarily is protective.

13 Role of Oestrogen and Progesterone Oestrogen in the maternal blood is primarily from the placenta. DHEAS and 16 – ortho hydroxy (OH) DHEAS from the foetus are converted to oestradiol and oestriol, respectively. The oestrogen receptors in the uterus are suppressed by progesterone throughout the pregnancy but at term, the so-called functional withdrawal of progesterone removes this suppression and allows the uterotonic action of oestrogens [1]. 1. Oestrogen lowers the resting potential and increases the contractility of the muscle. Progesterone raises the membrane potential and makes the muscle quiescent.

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2. The formation of gap junctions is promoted by oestrogen and lowered by progesterone. 3. Oestrogens are known to labilise the intracellular lysosomes and increase the release of phospholipase A2 enzyme, which is necessary for PG synthesis while progesterone has the opposite action. 4. Oestrogen increases the oxytocin receptors in the myometrium while progesterone inhibits it.

14 Role of the Mother 14.1 Oxytocin It is produced in a pulsatile fashion having a half-life of 3–4 min and is inactivated in the liver and kidney. • The number of oxytocin receptors rises in myometrial decidua at term. • Promotes PG release. Oxytocin induces contractions in a previously sensitised uterus. It also increases the force and frequency of contractions in an already contracting uterus. It increases intracellular ionic calcium levels leading to amplification of both frequency and duration of electrical discharges from myometrial cells. It also promotes the synthesis and release of prostaglandins (PGE2 and PGF2α) from the uterine decidua that results in myometrial contractility. Development of oxytocin receptors commences around 20th week of gestation and thereafter it remains unchanged until the beginning of onset of labour. However, there is a marked increase in myometrial sensitivity to oxytocin, mediated by oestrogens. Oxytocin receptors increase in late pregnancy, active labour and third stage of puerperium and lactation. Oxytocin does not play a major role in phase 2 but it is more important in phases 3 and 4 and the puerperium. Vasopressin: Octapeptide synthesised by hypothalamus and stored in posterior pituitary has structural similarity to oxytocin; it has considerable oxytocin activities in humans. Relaxin: It is a peptide hormone that activates collagenases and may have some effect of cervical ripening before labour. CRH: It has been shown to increase the contractile response of myometrium to circulating oxytocin as well as oxytocin-induced PG production from the foetal membranes and placenta in in vitro studies. Maternal CRH levels ↑ exponentially during the second half of pregnancy peaking at delivery. The source of this CRH is placenta and not maternal or foetal hypothalamus.

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Prostaglandins: These have a critical role in phase 3 parturition. Levels are increased in amniotic fluid, maternal serum and urine during labour. Receptors for PGE2 and PGF2α are expressed in uterus and cervix.

15 Mechanical Factors Distension and stretching of the myometrium also play a role. Thus, the ultimate aim of all these changes in phase 2 is the onset of uterine contractions in phase 3.

16 Phase 3 (Labour) This phase is the active phase of labour, which is actually divided into three stages. First stage: It starts with the onset of regular uterine contractions of increasing frequency, intensity and duration to bring about cervical effacement and dilatation—The stage of cervical effacement and dilatation. Second stage: Starts with end of first stage, i.e. when the cervix is fully dilated to 10 cm, and ends with delivery of the foetus or foetuses. This is the stage of foetal expulsion. Third stage: Begins with the delivery of the foetus and ends with the delivery of placenta. This is the stage of placental separation and expulsion. Fourth stage: 2 h after placental expulsion during which myometrium contracts with vessel thrombosis to stop bleeding from placental site. The latent phase precedes active labour by several hours during which there is slight discomfort with irregular contractions and slow effacement and dilatation.

17 First Stage It starts with the expulsion of blood-tinged mucus from the vagina, which is the ‘show’. It indicates that the process of labour has ensued or will start in a few hours. The characteristic of the uterine contractions of this stage is that they are painful. The possible explanations are: (a) Hypoxia of the contracted myometrium (b) Compression of the nerve ganglia in the cervix and lower uterus by contracting muscle bundles (c) Cervical stretching (d) Peritoneum stretching That is why when we give paracervical block with lignocaine, it produces pain relief because the nerve ganglia is being compressed in cervix and lower uterine segment [1].

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These contractions are involuntary smooth muscle contractions and are independent of extrauterine control. That is why when we give epidural analgesia for pain relief the uterine contractions are not abolished. Ferguson’s reflex: Mechanical stretching of the cervix increases the intensity and frequency of uterine contractions, which may be by release of oxytocin. When we do a sweep and stretch during per-vaginal examination, there is an increase in blood levels of PG F2 alpha metabolites. Duration of uterine contraction ranges from 30 to 90 s in active phase of labour, on an average 1 min. The uterus relaxes in between contractions to maintain blood supply to foetus. So if the lady goes in for sustained hyperstimulation, the foetus may go in for hypoxia. Intensity of contraction increases in the second stage. The anatomical uterine divisions that were initiated in phase 2 of parturition become increasingly evident. The difference can be appreciated even by abdominal palpation. The upper segment becomes thicker with each contraction and the lower segment becomes softer, distended and more passive. If the entire uterus contracts simultaneously, then the expulsion force may actually come down. Thus the upper segment contracts and lower segment receives it. One of the most intriguing problems in obstetrics is the mechanism of uterine action. To understand the physiology of normal labour and its abnormality, it is necessary to study the uterine musculature in pregnancy and its mode of control.

18 Myometrial Architecture Uterine musculature is arranged in three indefinite layers—external, internal and middle stratum. The middle stratum is the most important of all. The blood vessels pass from the external vascular area to the endometrium through this area. When the uterus contracts and retracts after the foetus and placenta are expelled at the end of labour, these vessels are compressed and kinked to shut off the blood supply to the placental area. Thus the open sinuses in the placental area stops bleeding and postpartum haemorrhage (PPH) is prevented.

18.1 Why the Smooth Muscles Can Bring About Efficient Contractions? The degree of smooth muscle shortening with contractions may be one order of magnitude greater than that attained in striated muscle cells. 1. Force in smooth muscle cells can be exerted in multiple directions. 2. Also the smooth muscle filaments are found in random bundles throughout the cells, which help in greater shortening and force generation in the uterine fundus.

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3. Greater multidirectional force generated in the fundus compared to lower segment allows expulsive forces to be directed downwards. The muscle fibres of the upper segment do not come back to their original length after contractions and become fixed at a shorter length; the tension however remaining the same as before contraction. The upper segment is the active part and it contracts down on its diminishing contents. Each new contraction starts where its predecessor left due to the retraction of upper segment. Now, when the uterus is a closed sac, the process of retraction of upper uterine segment should be accompanied by the stretching of the lower segment, to receive the contents from the upper uterus, i.e. the upper segment can contract only to the extent that lower segment stretches. The lower segment relaxes but it is not a complete relaxation. With each contraction of the upper segment the fibres become stretched after which they do not return to their previous length, but remain fixed as larger. Due to the upper segment thickening and thinning of lower segment, the boundary is formed between these two, which is marked by the ridge of the inner uterine surface—physiological retraction ring. In obstructed labour, the ring is prominent and forms a pathological retraction ring or Bandl’s ring [1]. Figure 4 depicts the formation of lower uterine segment. When the upper segment contracts, the lower segment dilates to allow passage of the foetus. This intrinsic property is what you call the polarity. For the labour process to progress, the contractions starting from the fundus should be strong and sustained, with less strong simultaneous contractions of the middle zone and relative inactivity of the lower zone. This is what you call the gradient of diminishing physiological activity. Uterus becomes elongated in the vertical dimension and shortened in the horizontal diameter with each contraction, which will actually increase the foetal axis

Fig. 4  Formation of lower uterine segment

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pressure by straightening the foetal vertebral column. This presses the upper pole of foetus firmly against the fundus. Other forces are the increased maternal intraabdominal pressure brought about by contraction of the abdominal muscles simultaneously with forced respiratory efforts with a closed glottis. If this is done in the first stage rather than the second stage, which usually happens with occipito-posterior positions, it may actually exhaust the mother. Due to the uterine contractions, changes of effacement and dilatation occur in the cervix, which is already ripened. Effacement is the taking up of the cervix over the presenting part, which converts a long cervix to a thin structure with a circular opening. Because the lower segment and cervix have less resistance during a contraction, a centrifugal pull is exerted on the cervix, which causes cervical dilation. The hydrostatic pressure of the amniotic sac dilates the cervical canal and leads to formation of fore bag of amniotic fluid. Even if the membranes are ruptured so long as the foetal part is closely apposed to the cervix, it can promote cervical dilatation. Foetal descent occurs in late first stage and second stage. A typical hyperbolic curve is formed when foetal head is plotted against a function of labour duration. In nulliparous, the descent is slow and steady while in multiparous, descent may be rapid. One of the marked changes in the late stages of labour is thinning of the central portion of the perineum, which changes from a 5 cm thick tissue mass to thin membrane-like structure less than 1 cm thick. This is also accompanied by dilated anus with protruding mucosa.

19 The Physiology of Uterine Muscle Contractions Contraction results from actin–myosin interactions, increased excitability of individual myometrial cells and promotion of intracellular cross-talk that permits synchronous contractions to develop. The individual myometrial cell contracts when the two filaments actin and myosin combine. This reaction requires increased availability of intracellular calcium, which may be provoked by oxytocin or PGF2α or both. Extracellular calcium may be transported into myometrial cells via calcium channels. Contractions of myometrial cells may be inhibited by progesterone and by the intracellular cyclic adenosine monophosphate (cAMP); β-mimetic agents as tocolytic work by this mechanism [5–7].

20 Actin–Myosin Interactions They are necessary for muscle contraction. For this, actin must be converted to a filamentous form. Actin must couple with myosin. So, for contraction, we need an ↑ in intracellular Ca2+ levels and vice versa. Intracellular Ca2+ increases ➔ cellular depolarisation follows. For example, PGF2α

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and oxytocin bind to their respective receptors during labour to open ligand-­ activated calcium channels and cause influx of Ca2+ from sarcoplasmic reticulum to lower electronegativity in the cell. Before labour, myocytes maintain a relatively high interior electronegativity. During relaxation, calcium ions are pumped back into the sarcoplasmic reticulum, which is an energy requiring process. A fall in Ca ions causes dephosphorylation of myosin chains and then it returns to resting state. Neural activity is not a prerequisite for myometrial contractions [15, 16].

21 Myometrial Gap Junctions Communication between myocytes is by the formation of gap junctions, which helps in the passage of currents as well as metabolites. Gap junctions consist of connexons, which are composed of six connexin proteins forming a conduit between coupled cells for exchange of waste, metabolites, ions etc. Optimal number and type of gap junctions are important for maintaining myometrial synchrony. Contraction-­ associated proteins (CAP) include oxytocin receptors, PGF receptor and connexin­43, which increase at the end of pregnancy. Smooth muscle cells of myometrium are arranged in longitudinal, transverse, oblique as well as in a criss-cross manner with intervening blood vessels known as living ligatures. The placental steroids cause growth of myometrium by hyperplasia and hypertrophy. With electron microscopy, it was found that plasma membranes from the two opposing cells have intermembranous proteins called connexins protruding through each membrane and spanning the gap between the membranes. They are the ‘gap junction’ and are actually the low-resistance pathways to the flow of excitation. They allow communication between adjacent cells, which may be electrical or metabolic or both. Electrical signals (e.g. action potentials) can be rapidly transmitted to all neighbouring cells leading to efficient contraction as a functional syncitium. These gap junctions increase before term and are higher during labour. Oestrogen and PG increase the formation of gap junctions while progesterone inhibits the formation of the same. The permeability of gap junctions to various substances appears to be regulated by both Ca ions and cyclic adenosine monophosphate (cAMP). It has been shown that the level of messenger ribonucleic acid (mRNA) (coding for the gap junction protein connexin-43) was elevated in human myometrium towards term and with the onset of labour [1].

21.1 How Do We Measure Uterine Contractions? The studies by Caldeyro-Barcia [1], demonstrate myometrial contractility during prelabour in the last quarter of pregnancy.

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Uterine contractility is the product of frequency and amplitude of contractions. The standard unit of measurement is the Montevideo unit (MVU). Contractions are deemed to be adequate if it is more than 200 MVU within 10 min.

22 Second Stage: Delivery of the Foetus Extends from the complete dilatation of the cervix to the expulsion of the foetus or foetuses. This stage may last for 1–2 h in a primigravida and half to 1 h in a multipara. Contractions are stronger in the second stage and are of a ‘bearing down’ character. The voluntary muscles also begin to act—the diaphragm and abdominal muscles. With these the foetus is pushed down through the dilated cervix and distended vagina and perineum leading to crowning of the head and ultimately the delivery.

23 Third Stage: Foetal Expulsion to Delivery of Placenta and Membranes The average duration may be few to 15 min. As the foetus is expelled, the uterus contracts on its reduced contents and comes at the level of umbilicus. This reduced size causes buckling of the area of placental implantation and placenta thickens, and the tension pulls the weakest part of the placental attachment—decidua spongiosa—from the uterine wall and separation of placenta follows. As it detaches, a retroplacental haematoma forms between placenta and decidua and the separation progresses. The membranes also detach and are peeled off the uterine wall partly by further contraction of myometrium and partly by traction that is exerted by the separated placenta as it descends.

24 Phase 4 (Involution Phase) Over the period of 4–6 weeks following delivery, described as the puerperium, multiple factors cause the uterus and cervix to shrink and return to prepregnant state. Local inflammatory processes resolve, oxytocin released in response to suckling aids the uterine involution and the endometrium starts healing and regenerating. The maternal hypothalamic-pituitary-ovarian (HPO) axis starts functioning again. In summary, a comprehensive understanding of the physiology of parturition, as described above, is important to the clinician because it can be applied to various clinical situations where we want to prevent preterm labour or we want to induce or augment labour. For example, progesterones, Ca channel blockers, magnesium sulphate etc. are used in preterm labour and there is use of sweep and stretch of cervix and PG for ripening and oxytocin for acceleration of labour. It also has clinical applications in first and second trimester pregnancy termination and prevention and control of postpoartum hemorrhage (PPH).

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References 1. Williams Obstetrics, 25th Edition. Book by Catherine Y. Spong, Jodi S Dashe, Steven L Bloom, Barbara L Hoffman; 2018. 2. Kelly RW. Pregnancy maintenance and parturition: the role of prostaglandin in manipulating the immune and inflammatory response. Endocr Rev. 1994;15(5):684–706. 3. Johnson TA, Greer IA, Kelly RW, Calder AA. Plasma prostaglandin metabolite concentrations in normal and dysfunctional labour. Br J Obstet Gynaecol. 1993;100(5):483–8. 4. Akgul Y, Holt R, Mummert M, Word A, Mahendroo M.  Dynamic changes in cervical glycosaminoglycan compositionduring normal pregnancy and preterm birth. Endocrinology. 2012;153(7):3493–503. 5. Akgul Y, Word RA, Ensign LM, Yamaguchi Y, Lydon J, Hanes J, et al. Hyaluronan in cervical epithelia protects against infection mediated preterm birth. J Clin Invest. 2014;124(12):5481–9. 6. Akins ML, Luby-Phelps K, Bank RA, Mahendroo M. Cervical softening during pregnancy: regulated changesin collagen cross-linking and composition of matricellular proteins in the mouse. Biol Reprod. 2011;84(5):1053–62. 7. Alperin M, Lawley DM, Esparza MC, Lieber RL. Pregnancy-induced adaptations in the intrinsic structureof rat pelvic floor muscles. Am J Obstet Gynecol. 2015;213(2):191 e1–7. 8. Badir S, Bajka M, Mazza E.  A novel procedure for the mechanical characterization of the uterinecervix during pregnancy. J Mech Behav Biomed Mater. 2013;27:143–53. 9. Benedetto C, Petraglia F, Marozio L, Chiarolini L, Florio P, Genazzani AR, et al. Corticotropin-­ releasing hormone increases prostaglandin F2 alpha activity on human myometrium in vitro. Am J Obstet Gynecol. 1994;171(1):126–31. 10. Berkowitz GS, Lapinski RH, Lockwood CJ, Florio P, Blackmore-Prince C, Petraglia F.  Corticotropin-releasing factor and its bindingprotein: maternal serum levels in term and preterm deliveries. Am J Obstet Gynecol. 1996;174(5):1477–83. 11. Bollapragada S, Youssef R, Jordan F, Greer I, Norman J, Nelson S. Term labor is associated with a core inflammatory response in human fetal membranes, myometrium, and cervix. Am J Obstet Gynecol. 2009;200(1):104.e1–11. 12. Casey ML, Mac Donald PC. Human parturition: distinction between the initiation of parturition and the onset of labor. In: Ducsay CA, editor. Seminars in reproductive endocrinology. New York, NY: Thieme; 1993. 13. Casey ML, Mac Donald PC.  The endocrinology of human parturition. Ann N Y Acad Sci. 1997;828:273–84. 14. Challis JR, Matthews SG, Gibb W, Lye SJ. Endocrine and paracrine regulation of birth at term andpreterm. Endocr Rev. 2000;21(5):514–50. 15. Chibbar R, Miller FD, Mitchell BF. Synthesis of oxytocin in amnion, chorion, and decidua may influence the timing of human parturition. J Clin Invest. 1993;91(1):185–92. 16. Kimura T, Takemura M, Nomura S, et al. Expression of oxytocin receptor in human pregnant myometrium. Endocrinology. 1996;137(2):780.

Mechanism of Labour Vinayachandran S. and Sajala Vimalraj

1 Introduction Labour and delivery, the process by which the mature foetus is expelled from the uterus, is not a passive process. It involves a complex interaction of uterine activity, the foetus and the maternal pelvis, to achieve a successful negotiation of this start of the human life.

2 Definition Labour is a physiologic process during which the viable foetus with membranes and placenta is expelled from the uterus per viam naturalem. It begins with the onset of regular strong uterine contractions, and dilatation and effacement of the cervix and ends with the birth of baby and expulsion of placenta and membranes [1, 2]. It is normal if: • • • • •

It has spontaneous onset, at term. It has vertex presentation (singleton). It is without undue prolongation. It terminates naturally with minimal aids. It is without any complications in foetus and mother.

V. S. (*) Malabar Medical College and Research Centre, Ulliyeri, Kozhikode, Kerala, India Government Medical College, Kozhikode, Kerala, India S. Vimalraj Malabar Medical College and Research Centre, Ulliyeri, Kozhikode, Kerala, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_2

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In a study at Parkland Hospital [2], only around 50% of labours met these stringent criteria defining normal labour. Any deviation from the above is termed abnormal labour or dystocia.

3 Power, Passage and Passenger [1–3] Definition: The positional changes in the presenting part required to pass through the pelvic canal constitutes the mechanism of labour. And these mechanisms are a result of the interactions of the three major components of the labour process—the Power, the Passage and the Passenger. Let us take a look at some of the relevant features of these three components and some foeto-pelvic relationships. Power: It comprises of the strong uterine contractions and the voluntary efforts of the mother, viz. the contractions of the abdominal muscles and the diaphragm, which propels the foetus forwards. Uterine contractions are classically described as adequate if there are three to five contractions every 10 min, and the duration of each contraction is 40–45  s with adequate relaxation in between. Measured in Montevideo units (MVU), these contractions are accepted to be adequate if they are between 200 and 250 MVU. Passage: The structure of the bony pelvis comprising of the two innominate bones (constituted by fusion of the iliac, pubic and ischial bones), the sacrum and the coccyx. The pelvis is divided into the false and true pelvis, above and below the linea terminalis, respectively. While full description of the bony pelvis is beyond the scope of this chapter, some aspects important to the mechanism of labour will be touched upon. The true pelvis is described as having four imaginary planes, as shown in Fig. 1:

Fig. 1  The planes of the pelvis

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1. Inlet—bounded by the promontory and alae of the sacrum posteriorly, the linea terminalis laterally and anteriorly by pubic rami and the pubic symphysis. When the maximum transverse diameter of the foetal skull, the biparietal diameter (BPD), has crossed the inlet, the foetal head is said to have engaged. 2. The plane of greatest dimensions—at the level of junction of S2 and S3 vertebra; does not have much clinical significance. 3. The plane of least pelvic dimensions—in the midpelvis, at the level of the ischial spines. It extends from the apex of the subpubic arch, through the ischial spines to the S4–S5 junction and is usually 10 cm or slightly greater, in the transverse plane. This is a clinically important plane, which is used to describe the station of the head and, since it is the smallest plane, arrest of descent is most likely to take place at this plane. 4. Pelvic outlet—is bounded by the subpubic angle and the pubic rami anteriorly, laterally by the ischial tuberosities and the sacrotuberous ligaments and posteriorly by the tip of the sacrum or the sacrococcygeal joint. In absence of bony disease, the pelvic outlet rarely obstructs vaginal delivery. The pelvis is shaped in such a way that the inlet is a relatively transverse oval, the midcavity almost circular and the outlet is more of an antero-posterior oval, so that the foetus must undergo rotational fit to its diameters within the available space, as shown in Fig. 2. Of the four pelvic shapes described by Caldwell-Moloy, the gynaecoid pelvis, seen in almost 50% of the women, would seem most conducive to vaginal delivery. Passenger: The foetal skull, which is most frequently the presenting part, is an ovoid with a larger antero-posterior diameter than a transverse diameter and it must negotiate its journey through the maternal pelvis during labour. The bones at the base of the skull are ossified and protect the brainstem. The cranium or vault is made up of the occipital bone and two each of temporal, parietal and frontal bones. These bones, which are poorly ossified, are joined only by membranes or the sutures, permitting overlapping under pressure, or ‘moulding’, which

Inlet–a relatively transverse oval Midcavity–almost circular Outlet–antero posterior oval

Fig. 2  The shape of the various planes in the pelvis

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Fig. 3  Diameters of the fetal skull

helps the foetus overcome mild degrees of cephalopelvic disproportion. The sagittal, coronal, lambdoidal and frontal sutures also help the examiner identify the position of the foetal head in the pelvis. The larger anterior fontanel is at the junction of the sagittal, frontal and coronal sutures, while the smaller posterior fontanel is at the junction of the sagittal with the lambdoidal sutures. The major landmarks and diameters of the foetal skull are shown in Fig. 3: In normal labour, in a vertex presentation, the presenting diameter is the sub-­ occipito-­bregmatic, which is 9.5 cm.

4 Foeto-Pelvic Relationships At the onset of labour, the position of the fetus with respect to the birth canal is crucial to the mechanism of labour and some important relationships include fetal lie, presentation, attitude and position (Table 1). Lie—relationship of the longitudinal axis of the foetus with that of the mother. Longitudinal—where both the axes are parallel. Transverse—both axes are perpendicular. Predisposing factors are multiparity, placenta praevia, hydramnios and uterine anomalies. Oblique—unstable lie, occasionally seen, where the foetal and maternal axes may cross at a 45° angle. Usually converts to a longitudinal or transverse lie during labour. Presentation—that part of the foetal body that overlies the pelvic inlet, typically felt through the cervix on vaginal examination. In a longitudinal lie:

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Mechanism of Labour Table 1  Various presentations and their incidence Lie • Longitudinal: 99.5%

Presentation • Cephalic: 96%—97%

Attitude • Flexion • Military • Partial extension • Complete extension

• Breech: 3%—4% Complete Frank

• Transverse or oblique: 0.5%

Footing: single, double Kneeling: single, double • Shoulder

• Flexed hips and knees • Flexed hips and extended knees • Extended hips and knees • Extended hips; flexed knees • Variable

Presenting part • Vertex—posterior part occupit. • Vertex—medium part occupit • Brow— forehead(frontum)(Fr) • Face—chin (mentum) (M)

Buttocks—Sacrum (S) Buttocks—Sacrum (S) Feet—Sacrum (S) Knees—Sacrum (S) Shoulder, arm, trunk— Scapula (Sc)

Cephalic—more common because in an attitude of flexion, the podalic pole, breech is bulkier than the cephalic pole, and hence it usually occupies the roomier fundus of the piriform-shaped uterus. Breech—the podalic pole overlies the pelvic outlet. It is seen in 2–3% cases at term, though at 28 weeks almost 25% foetuses present as breech. In transverse lie, it is the shoulder that usually presents. Attitude—relationship of the foetal parts to each other. Normally there is universal flexion, where the spine is convex and the head is sharply flexed, with flexion at the hip and knee joints and the arms crossed over the chest. This ensures maximum utilisation of space in the uterine cavity.

5 Presenting Part and Denominator • Presenting part—the most dependent part of the foetus, lying nearest to the cervix. • Denominator—arbitrary bony fixed point on presenting part, used to describe the position. –– Cephalic—Occiput/mentum/sacrum. –– Brow—frontal eminence. –– Shoulder—acromion.

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Fig. 4  Various positions in an occipital position

Foetal position: This refers to the relationship of an arbitrarily fixed portion of the foetal presenting part to the maternal pelvic quadrants. The foetal occiput, chin (mentum) and the sacrum are the denominators in the vertex, face and breech presentations, respectively, and their positions in the anterior or posterior and right or left quadrants of the maternal pelvis determine eight possible positions in each presentation. As shown in Fig. 4, in an occiput presentation, the position may be occiput anterior (OA), left occipito-anterior (LOA), left occipito-transverse (LOT), left occipito-posterior (LOP), occipito-posterior (OP), right occipito-posterior (ROP), right occipito-transverse (ROT) and right occipito-anterior (ROA). OA is just below the symphysis pubis and the rest are all at 45° to the previous position, in a clockwise rotation. Approximately two-thirds of all vertex presentations are in the left occipito-­ anterior position and most of the further discussions regarding diagnosis and mechanism of normal labour will be described for this position.

6 Diagnosis of Foetal Presentation and Position Abdominal palpation, vaginal examination and occasionally sonography are used to diagnose foetal presentation and position at the onset of labour, as also to monitor its progress. Abdominal palpation: With the mother in the supine position and comfortably relaxed, after a thorough general examination, the Leopold’s manoeuvres are used to diagnose the foetal lie and presentation. The first manoeuvre identifies the large irregular mass in the fundus, which is the breech of the baby. The second umbilical grip shows the hard band of resistance, the foetal back on the left side and small irregular mobile parts on the right side. The back may be directed anteriorly, transversely or posteriorly, giving an indication of the position of the foetal head in the pelvis.

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The third manoeuvre, or first pelvic grip, shows a hard round ballotable mass that is the foetal head. The fourth manoeuvre tells us whether the foetal head is engaged and whether the attitude is that of flexion, when the cephalic prominence will be on the side opposite to the back. With practice, a rough estimation of the foetal weight and the amount of liquor too can be determined.

7 Vaginal Examination After determining the position, consistency, dilatation and effacement of the cervix, the foetal presenting part is examined. Once the cervix has opened up in labour, the palpation of the various sutures and fontanels aid in diagnosing the presenting part and the position. After ruling out a face or breech presentation, sweeping the fingers antero-posteriorly helps to delineate the sagittal suture. Along the suture, the two fontanels are then palpated to ascertain the position of the occiput and the attitude of the foetus. Finally, the level to which the presenting part has descended, in relation to the ischial spines, is examined to determine the station. In the LOA position, which is the commonest, the sagittal suture is in the transverse pelvic diameter when the head engages and then rotates 45° anteriorly to the right oblique diameter, with the occiput between the 2 o’clock and 3 o’clock positions, as shown in Fig. 5. Sonography: With experience a clinician can determine the lie and presentation with almost 70–80% accuracy, but in obese women and those with rigid abdominal wall, an ultrasound examination will help assess the lie and the position of the back. Of late, ultrasonography (USG) in labour has been described to assess the progress of labour, which will be dealt with later. Fig. 5  LOA position

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8 Mechanism of Labour First described by William Smellie in the eighteenth century [1–3]. • Engagement. • Cardinal movements with considerable overlapping • Descent, flexion, internal rotation, extension, restitution, external rotation –– Sequential movements with temporal overlap—descent and flexion seen concomitant with engagement and internal rotation (Fig. 6). a

b

c

d

e

f

Fig. 6  Cardinal movements of labour: (a) onset of labour, LOA; (b) descent and flexion; (c) internal rotation, LOA to OA; (d) extension; (e) restitution, OA to LOA; (f) external rotation, LOA to LOT

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• Also, there is a change in attitude of the foetus with the strong contractions, especially after the head has descended into the pelvis. There occurs a ­straightening of the foetus, with loss of dorsal convexity and closer application of the extremities to the torso, so that the foetal ovoid is transformed to a cylinder. This aids easy navigation, because the smallest possible cross-section passes through the birth canal, and so the force of uterine contraction is better transmitted to the head, which causes mechanical stretching of the lower segment and opening up of the cervical canal. Let us take a look at each of these in detail.

8.1 Engagement Biparietal diameter: The greatest transverse diameter in an occiput presentation is the BPD and when it has passed through the inlet, the head is said to have engaged. This occurs in the last few weeks of pregnancy or at the start of labour. Usually, the foetal head enters the pelvis in the transverse or oblique diameter. In order to accommodate to the pelvis, the foetal head deflects to a more anterior or posterior position in the pelvis, so that the sagittal suture may lie a little towards the symphysis pubis or the sacral promontory. If the sagittal suture approaches the sacral promontory, it is the anterior parietal bone that is felt by the examining fingers and the condition is called anterior asynclitism. Similarly, if it approaches the symphysis pubis, it is the posterior parietal bone that is felt—posterior asynclitism. Moderate degrees of asynclitism and its successive shifting aid descent, but a severe degree of asynclitism can cause cephalopelvic disproportion, even in a normal pelvis.

8.2 Descent • Aided by: –– Uterine contraction and retraction—direct pressure on foetus –– Straightening of foetal ovoid, especially after Rupture of Membranes –– Bearing down efforts –– Pressure of the amniotic fluid • Continuous process—slow in first stage, especially if head engaged prior to labour as in primigravida. • Increased in second stage.

8.3 Flexion • When the descending head meets resistance from cervix, pelvic walls and pelvic floor, it flexes and there is a reduction in presenting diameter from the longer occipito-frontal diameter to the shorter sub-occipito-bregmatic diameter.

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8.4 Internal Rotation • As flexed head meets resistance of pelvic floor, it rotates internally 1/8th of a circle, so that the occiput gradually moves towards the symphysis pubis. The levator ani muscle fibres, which make up most of the pelvic floor, are directed forward and downward giving a gutter shape to the pelvic floor. These muscle fibres are stretched as head is pushed down with contractions and as it wears off, the elastic recoil of the muscles pushes the occiput towards the midline, and the forward inclinations of the side walls of the cavity pushes the occiput anteriorly (Fig. 6). • The narrow, (almost circular) plane through the interspinous diameter transversely and long antero-posterior (AP) diameter of outlet make this necessary. • As always, internal rotation is also accompanied by descent and occurs normally at the pelvic floor. The shoulders remain in left oblique diameter (if the initial position was LOT, shoulder rotates 1/8th of a circle to LOA, because the neck cannot withstand a 90° torsion).

8.5 Extension • If extension does not occur, the flexed head will be pushed down on the posterior portion of perineum and cause tears. The force exerted by uterus acts more posteriorly and a second force (upwards and forward) by resistant pelvic floor and symphysis acts anteriorly. The resultant vector is in the direction of the vulvar opening (more forward)—causing extension of the foetal head. • This brings the base of the occiput under the pubic arch, descent continues and the maximum diameter of the head (BPD) distends the vulval outlet and when it does not recede when the contraction wears off, crowning is seen. The vaginal opening progressively distends and more of the occiput is visible and over the next few contractions, the head is born as the occiput, bregma, forehead, nose, mouth and finally the chin are successively delivered. As the chin is released from the anterior margin of the stretched perineum, the chin drops and comes to lie in close contact with the maternal anus.

8.6 Restitution • Visible passive movement of the head due to untwisting of the neck sustained during internal rotation, and the occiput is directed towards the left ischial tuberosity.

8.7 External Rotation • Externally visible rotation of the head (further 1/8th circle) due to internal rotation of the shoulders—so shoulders move from the left oblique diameter (due to same factors that caused internal rotation of the head) and come to lie antero-­ posteriorly and occiput points laterally to maternal left thigh (Fig. 6).

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8.8 Birth of Shoulders and Trunk • With further descent the anterior shoulder escapes below symphysis pubis by lateral flexion, posterior shoulder sweeps over the perineum and then the rest of the trunk is expelled out.

9 Stages of Labour First Stage: From onset of labour to full cervical dilatation. • Dilatation and effacement of the cervix and formation of lower segment aided by: –– Uterine contraction and retraction—permanent shortening of uterine muscle fibres –– Polarity of uterus—cervical dilation and formation of lower segment –– Foetal axis pressure—straightening of foetal spine with contraction –– Pressure by forewaters, which helps dilate the cervix Second Stage: From complete cervical dilatation to foetal delivery. • Propulsive—full dilatation till head touches the pelvic floor. –– After full dilatation, liquor has drained, reduced volume. –– Stronger contraction and retraction—uterus becomes elongated during contraction with reduced AP and transverse diameters. –– Increased downward thrust—pelvic floor offers resistance but this is counterbalanced by the power of retraction and foetus is gradually expelled against the resistance offered by the pelvic floor. • Expulsive—perineal phase; bearing down aids the expulsion. –– Uterine cavity permanently reduced in size. Third Stage: From delivery of the foetus till expulsion of the placenta. Fourth Stage: The 1–2 h following delivery—the golden hours—where the uterus is contracting actively, and intensive monitoring must be continued, since many complications occur at this stage, which, if managed immediately, reduces maternal morbidity and mortality. Occipito-posterior position: In approximately 20% of labours, the foetus enters the pelvis in the occipito-posterior (OP) position, the ROP being commoner than the LOP. This is more likely if the fore pelvis is narrow or if the placenta is situated anteriorly. In most of these cases, the mechanism of labour is identical, except that the occiput has to internally rotate 135° to reach the symphysis pubis (or 90° from a transverse position). This is promoted by effective contractions, adequate flexion and the average size of the baby, and, as expected, may take slightly longer time than in LOA positions in some patients. In 5–10% cases, rotation may not take place at all or be incomplete and we have a deep transverse arrest or a persistent occipito-­posterior, both of which represent deviation from normal mechanism of labour.

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10 Foetal Head Shape Changes 10.1 Moulding It is an alteration of the bony foetal head shape, due to the external compressive forces during labour. In LOA positions, moulding results in a shortened sub-­ occipito-­bregmatic diameter, with a corresponding lengthening of the perpendicular vertico-mental diameter. The degree to which the head is capable of moulding decides whether vaginal delivery is possible in some cases of minor degrees of cephalopelvic disproportion. Most cases of moulding resolve within a week after delivery.

10.2 Caput Succedaneum In vertex presentations, the labour forces cause the portion of the foetal scalp overlying the cervix, especially before complete cervical dilatation, to become oedematous. This is called caput succedaneum and is usually only a few millimetres thick. In some cases, however, it can be so extensive that it becomes difficult to palpate the sutures and fontanels and causes a misjudgement of the station of the presenting part. It is usually at the most dependent area, so it can help deduce the original foetal head position. It also resolves within few days, and needs to be differentiated from a cephalhaematoma.

10.3 Cephalhaematoma This is haemorrhage under the periosteum caused by trauma to the skull due to prolonged pressure against the cervix, perineum or pubic bones, trauma due to ventouse or forceps or in precipitate labour. The swelling appears a few hours after birth, does not cross the suture lines and is reabsorbed slowly, taking 6–12 weeks to disappear. The above changes are shown in Fig. 7.

Fig. 7  Moulding, caput succedaneum and cephalhaematoma

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11 What Is Normal Labour Progression? Determining whether labour is progressing normally [4] is a key component of intrapartum care. But determining when labour has started, measuring its progress and deciding whether it is normal or not, is difficult. Traditionally, normal progress of labour was defined as per Friedman’s criteria [5], described from his study in the 1950s of 500 nulliparous and 500 parous women in labour. Those who fell within the 5th and 95th centile were considered to have normal progress and thus came about the partograph that we use, which pegs dilatation at 1.2  cm/h in nulliparas and 1.5  cm/h in multiparas, resulting in a sigmoid curve showing normal progress. He had divided the phases of labour into a preparatory phase, a dilatation phase and a pelvic phase. First stage: From onset of labour (time when there are regular contractions every 3–5 min, for more than an hour) to full cervical dilatation (as first identified on vaginal examination). Both are impossible to determine precisely. This first stage consists of a latent phase, characterised by gradual cervical change, and an active phase, with more rapid cervical changes. The duration of the latent phase is very variable and may last even up to 18–20  h in a nulliparous and 12–14  h in a multiparous woman. Hence, if the latent phase is excluded from the record of labour, most labour curves show remarkable similarity. The active phase of labour was traditionally defined as beginning at a dilatation of 3–5 cm. However, more recent studies by Zhang et al. [6] who studied data from the Consortium of Safe Labour, which included 62,415 labouring women, and described the time spent in labour resulting in vaginal birth, showed that the active phase can start at a more advanced stage, i.e. 6 cm (after which, most labours are seen to progress at a similar rate, with cervical dilatation at 1–2 cm/h). Before 6 cm, about 50% of the patients progressed at a rate slower than 1–2 cm/h, and many nulliparous who eventually delivered vaginally even took over 6 h to dilate from 4 to 5 cm and over 3 h to dilate from 5 to 6 cm (Fig. 8). Thus, the normal rate of cervical dilatation between 4 and 6 cm may be much slower than described by Freidman and mostly reflects the shallow slope of the latent phase rather than a protracted active phase. A deceleration phase was also not observed in these studies. Dilatation can thus be slower than originally described and yet be normal, with a vaginal delivery and a normal neonate. Since these data are contemporary and more inclusive, these are the basis for changes in practice of assessment and management of labour currently. The Labour Progression Study (LaPS) from Norway [8] compared labour outcome in two groups, managed according to the World Health Organisation (WHO) partogram and according to the contemporary partogram based on Zhang’s data, and found that there were no difference in caesarean section (CS) rates and adverse outcomes in the two groups. However, the Norwegian population characteristics were not generalizable to all. Second stage: From full cervical dilatation till delivery of the foetus. The median duration for second stage is as follows (Zhang et al.). • Nulliparous without epidural—0.6 h (95th centile—2.8 h)

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Fig. 8  Contemporary estimates of labour duration by dilation at admission; the 95th percentiles of cumulative duration among parity = 1. Illustrated is the 95th percentiles of cumulative labour duration in parity  =  1 and plotted as staircase lines based on the cervical dilation observed at admission, and centimetre by centimetre until full cervical dilation. (Louise Lundborg et  al. 2020 [7])

• With epidural—1.1 h (95th centile—3.6 h) • Multiparous without epidural—0.2 h (95th centile—1.3 h) • With epidural—0.4 h (95th centile—2 h)

12 The WHO Labour Care Guide (LCG) In view of recent studies, there was a lot of concern that earlier dictums for intervention based on the older partograms, which took into consideration the 1 cm/h rate of cervical dilatation, might be flawed and that more time may be given to labouring women, provided the maternal and foetal condition was good. This was to be ensured by allowing a companion to the labouring mother, maintaining adequate hydration and ambulation and monitoring the foetal hearts diligently—by hand-held Doppler. Thus, the new WHO Labour Care Guide [9] was designed, with no action and alert lines, but using alerts if any of the above parameters were abnormal,

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aiming to give more time to allow for successful vaginal delivery. If further data affirm its safety and applicability, it is set to make a paradigm shift in the way labour is managed. Standing and walking shorten the first stage of labour by >1 h and reduce the rate of caesarean delivery [1]. If the membranes have not spontaneously ruptured, amniotomy (artificial rupture of membranes) is advocated routinely by some obstetricians. This accelerates the labour, and meconium-stained amniotic fluid may be detected earlier. Artificail rupture of membranes (ARM) facilitates internal foetal monitoring to confirm foetal well-being. Amniotomy is contraindicated with human immunodeficiency virus (HIV) infection or hepatitis B or C, so that the foetus is not exposed to these.

13 Ultrasonography (USG) in Labour Second stage complications can add to morbidity and mortality for the mother and the neonate. Digital examination for cervical dilatation, foetal head descent and rotation has limited accuracy and reproducibility. Intrapartum transperineal USG has, of late, been used to predict delivery time, mode of delivery and success of vaginal delivery, because it is not affected by increasing caput succedaneum and deformity of the foetal skull as labour progresses. International society of ultrasound in obstetrics and gynaecology (ISUOG) guidelines currently recommend the use in prolonged second stage of labour (Level of evidence 2+, grade B recommendation) [10–13]. Various parameters that have been suggested include: • Angle of Progression (AoP): The angle between a line through the long axis of the pubic bone and a line from the anterior edge of the pubis to the leading edge of the foetal head in the maternal midsagittal position. The narrower the AoP, the higher the position of the foetal head. The time to delivery is shorter as the AoP increases. • Midline angle (MLA): The angle between the midline of the foetal head and the AP axis of the maternal pelvis in a transverse section. The time to delivery is shorter as the MLA increases. • Head–symphysis distance (HSD): The distance between the lower border of the symphysis pubis and the nearest point of the foetal skull along a line passing perpendicular to the long axis of the symphysis pubis and tangential to its lower border. Studies have shown a statistically significant smaller HSD in women who had spontaneous vaginal delivery [14]. • Head to Perineum distance (HPD): The shortest distance from the outer bony limit of the foetal skull to the skin surface of the perineum, measured by transperineal USG in transverse view. This has been used to predict success of induction of labour (IOL). It is more objective, accurate and less invasive than a digital examination. ­According to Eggebo et al., HPD of 40 mm is predictive of vaginal delivery, while longer HPD correlated with CS. It can also be correlated with AoP, because the two measurements evaluate the foetal head station from two viewpoints—the HPD, externally to the perineal skin and the AoP, internally to the pubic bone.

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Cervical length and cervical angle are other parameters that have been studied. Cervical length of 90° correlated with vaginal birth. Cervical length and cervical angle by trans vaginal ultrasound (TVS) are more objective and can predict success of IOL [15]. Persistent OP positions can also be diagnosed with smaller AoP and a greater HSD. Visual biofeedback to the parturient, using real-time USG screens, helps the parturient see the descent of the foetal head and the effect of the bearing down efforts and has been shown to improve maternal effort and motivation [16].

14 Management of Normal Labour 14.1 When to Admit? Admission is advised when membranes have ruptured or if contractions are lasting at least 30 s and occurring regularly at intervals of about 6 min or less with increasing frequency. Following are noted: • • • •

Regular and sustained painful uterine contractions Bloody show Membrane rupture Cervical effacement

If these criteria are not met, the mother might be in false labour, and is kept under observation and, if labour does not begin within several hours, is sent home. Blood pressure, heart and respiratory rates, temperature and weight are recorded, and oedema is noted. A urine specimen is collected for protein and glucose analysis, and blood is drawn for a complete blood count (CBC), blood typing and antibody screening. If routine laboratory tests were not done during prenatal visits, they should be done, including screening for HIV, hepatitis B, syphilis and group B streptococcal infection. A physical examination of size, position and presentation of the foetus, using the Leopold manoeuver, foetal heart sounds as well as location for auscultation and strength, frequency, and duration of contractions are recorded. Cervical dilation is recorded in centimetres as the diameter of a circle; 10 cm is considered complete. Effacement is estimated in percentages, from zero to 100%. Because effacement involves cervical shortening as well as thinning, it may be recorded in centimetres using the normal, uneffaced average cervical length of 3.5–4.0 cm as a guide. Station is expressed in centimetres above or below the level of the maternal ischial spines. Ischial spines correspond to 0 station; levels above (+) or below (−) the spines are recorded in cm increments. Foetal lie, position and presentation are noted.

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14.2 Preparation for Delivery Women are admitted to the labour suite for frequent observation until delivery. In active labour, little is given orally to prevent possible vomiting and aspiration during delivery or in case emergency delivery with general anaesthesia is necessary. Shaving or clipping of vulvar and pubic hair can raise the risk of wound infections and hence not advocated [17] (Basevi et al., Cochrane Review 2008). Routine use of enema is not advocated [18]. An intravenous (IV) infusion of Ringer’s lactate may be started; in a normal labour of 6–10 h, women should be given 500–1000 mL to prevent dehydration during labour and haemoconcentration and to maintain an adequate circulating blood volume. Intravenous catheter provides immediate access for drugs or blood if needed. Fluid preloading is valuable if epidural or spinal anaesthesia is planned. If instrumental or caesarean delivery seems unlikely, women may drink clear liquids.

References 1. Seshadri L, Arjun G. Essentials of obstetrics. 2nd ed. Gurgaon: Wolters Kluwer. 2. William’s obstetrics. 24th and 25th ed. New York, NY: McGraw Hill Education. 3. Human labour and birth, Oxorn-Foote, sixth international edition, McGraw Hill Education. 4. Zhang J, Troendle J, Mikolajczyk R, et al. The natural history of the normal first stage of labor. Obstet Gynecol. 2010;115:705. 5. Friedman E. The graphic analysis of labor. Am J Obstet Gynecol. 1954;68:1568. 6. Zhang J, Landy HJ, Branch DW, et al. Contemporary patterns of spontaneous labor with normal neonatal outcomes. Obstet Gynecol. 2010;116:1281. 7. Lundborg L, et al. First stage progression in women with spontaneous onset of labor: a large population-based cohort study. PloS One. 2020;15(9):e0239724. https://doi.org/10.1371/journal.pone.0239724. PMCID: PMC7518577, PMID: 32976520. 8. Dalbye R, et al. The labour progression study (LaPS): duration of labour following Zhang’s guideline and the WHO partograph—a cluster randomised trial. Midwifery. 2020;81:102578. https://doi.org/10.1016/j.midw.2019.102578. 9. World Health Organization. WHO labour care guide: user’s manual. Geneva: World Health Organization; 2020. Licence: CC BY-NC-SA 3.0 IGO. C. 10. Ghi T, Eggebe T, Lees C, et al. ISUOG, practice guidelines: intrapartum ultrasound. Ultrasound Obstet Gynecol. 2018;52:128–39. 11. Yonetani N, Yamomoto R, et al. Prediction of time to delivery by transperineal ultrasound in second stage of labour. Ultrasound Obstet Gynecol. 2017;49:246–51. 12. Ciaciura-Jarno M, Cnot W, Woktowikz D, et al. Evaluation of selected ultrasonography parameters in the second stage of labour in prediction modeof delivery. Ginekol Pol. 2016;87:448–53. 13. Gluzak M, Dziadecki W, et al. Evaluation of sonographic assessment of the progress of labour. Ginekol Pol. 2015;86(2):126–31. 14. Youssef A, Maroni E, Cariello L, et al. Fetal head-symphysis distance and mode of delivery in second stage of labour. Acta Obstet Gynecol Scand. 2014;93:1011–7. 15. Pandis GK, Papageorghiou AT, et al. Preinduction sonographic measurement of cervical length in the prediction of successful induction of labour. Ultrasound Obstet Gynecol. 2001;18:623–8. 16. Gilboa Y, Frenkel TI, et al. Visual biofeedback using transperineal ultrasound in second stage of labour. Ultrasound Obstet Gynecol. 2018;52:91–6. 17. Vittorio Basevi, Tina Lavender. Routine perineal Shaving on admission in labour. Cochrane Database Syst Rev. 2014;2014(11):CD1236. https://doi.org/10.1002/14651858. CD001236.pub2. 18. Reveiz L, et al. Enemas during Labour. Cochrane database Syst Rev. 2013;2013(7): CD000330. https://doi.org/10.1002/14651858.CD000330.pub4.

Cephalopelvic Disproportion Priyankur Roy, Roli Parvat, and Athulya Shajan

1 Types of Pelvis According to Caldwell-Moloy classification of pelvic types (1933), four types of female pelvis were described in relation to the cavity, side wall, ischial spines, sacrum and sacrosciatic notch. Overall the course and outcome of labour depend on the type of pelvis. Most common type of pelvis is gynaecoid pelvis (50%) of cases. Normally, gynecoid and android pelvis are ideal for the normal vaginal delivery. Actually, the majority of pelvis is of mixed types. The clinical rationale for categorising pelvis was to be able to predict various mechanisms of labour and the possibility of cephalopelvic disproportion [1] (Table 1).

P. Roy (*) Consultant Roy Clinic, Saharsa, Bihar, India R. Parvat Consultant BHU, Varanasi, India A. Shajan JMMCH, Thrissur, Kerala, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_3

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Shallow Straight Wide and shallow Broad and well curved Not prominent, blunt

85–90 10 cm

Occipitolateral or oblique occipitoanterior Transverse or oblique Easy anterior rotation No difficulty

Cavity Side wall Sacrosciatic notch Sacrum Ischial spine

Subpubic angle Transverse diameter of outlet

Position

Diameter of engagement Internal rotation Delivery

50% Slightly oval in transverse axis

Incidence Pelvic inlet

Gynaecoid

Occipitolateral or oblique occipitoposterior Transverse or oblique Difficult anterior rotation Difficult delivery with chances of deep transverse arrest and perineal injuries

Funnel shaped and deep Convergent Narrow and deep Straight-flattened and long Prominent and narrow interspinous diameter 60–75 Less than 10 cm

20% Heart shape—triangular

Android

Table 1  Summary of classical findings of different types of pelvis [2]

Anteroposterior Non-rotation Face to pubis delivery

Direct occipitoposterior position

Deep Divergent Wide and shallow Long and narrow Not prominent; may have narrow interspinous diameter More than 90 More than 10 cm

25% Oval in AP axis

Anthropoid

Transverse Anterior rotation No difficulty, deep transverse arrest may occur

Occipitolateral

Shallow Divergent Narrow and small Broad flat and concave Not prominent, blunt and widely separated More than 90 More than 10 cm

Platypelloid  36 weeks, as the risk of head entrapment is increased. • Previous scarred uterus—as it itself is risky for the patient. • Intrauterine foetal growth restriction—approximately half of the perinatal deaths in the Term Breech Trial were in intrauterine growth-restricted foetuses. Chronic placental insufficiency is already present in these cases. Also, unavoidable cord compression occurs during the second stage of labour leading to increased chances of foetal acidosis. • Abnormal Doppler studies. • Hypertensive disorders of pregnancy. • Gestational diabetes mellitus. • Oligohydramnios. • Previous history of abruption. • Rh isoimmunisation. • Human Immunodefeciency Virus (HIV) infection is not a contraindication.

11 Timing and Counselling Proper counselling of the patient is needed before performing the procedure, discussing about the risks and benefits involved and that the procedure is not always successful. Chances of uterine rupture, premature rupture of membranes (PROM), foetomaternal haemorrhage, abruption, foetal distress, cord compression, failure of the procedure and reversion should be talked about in detail. Consent has to be taken

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from the patient. Ideal time to perform ECV is after 36 weeks and before 37 weeks as chances for the patient to go in labour after 37 weeks are more. Secondly, if there is any complication leading to foetal distress during the procedure, the baby could be delivered by caesarean section immediately without increasing the risk of early preterm morbidity. Performing ECV earlier might make the baby susceptible to reversion into breech.

12 Preparation All facilities to perform emergency caesarean section should be there and the availability of operation theatre (OT) staff and paediatrician should be ensured. Patient preferably should be Nil per Os (NPO) for at least 4–6 h. Pretest Non Stress Test (NST) should be done to rule out foetal distress. Ultrasound should be done to confirm the presentation, foetal well-­being, localisation of placenta and amount of liquor, and for excluding foetal and uterine anomalies as well as also to see for the foetal back. Procedure can be done in labour room. Clinical pelvimetry is done. Tocolytics: Routine administering of tocolytics is not recommended but can be considered as an option after one failed attempt. Few studies (Fernandez et al. [16]) have compared the success rate with and without tocolytics, finding significantly higher success rate of 52% with and 27% without tocolytics [16]. ACOG [17] supports the use of tocolytics, 250 μg terbutaline prior to the procedure. Many studies have compared different uterine relaxants and tocolytic agents like calcium channel blockers, atosiban, nitroglycerin and betamimetic agents, with varying and inconclusive results (Velzel 2017) [18]. A Cochrane review in 2004 of six trials has well proven the reduced failure rate and caesarean section rates with tocolytics [19]. If used, the dose should be as follows: terbutaline 0.25 mg subcutaneously or in 5 mL normal saline over 5 min intravenously/terbutaline 0.5 μg/min intravenously over 15–20  min/ritodrine 0.2  mg/min intravenously over 15 min/nifedipine 10 mg orally. Some studies have proven better results with the foetal vibroacoustic stimulator as the foetus may start kicking facilitating the version [20]. Regional Analgesia: Regional analgesia used along with tocolysis has also increased the success rates without increasing the complication rates in few studies like Khaw and Weiniger. Cochrane review in 2004 [19], with five randomised controlled trials (RCTs), showed two trials with good success rates but three trials showed no extra benefit of spinal analgesia.

13 Technique Position the women with 45° lateral tilt and her back supported against the wall by a cushion. Ultrasound gel can be used to reduce friction. Forward Somersaulting: Preferred if the foetal back is downwards. The breech is lifted up by the fingertips of clinicians’ both hands, and with one hand the breech is pushed backwards towards the fundus by the edge of open hand

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and the foetal head is simultaneously flexed and moved in towards the pelvis continuously in forward direction by the other hand. When the lie becomes transverse, the hands are interchanged and the same process continues. Backward Somersaulting: Preferred if the foetal back is upwards. The foetal head is grasped and pushed backwards and the podalic pole I compressed and pushed forwards till the lie becomes transverse. Again the hands are interchanged, and the process continues till the lower pole is occupied by the foetal head. Cephalic presentation is confirmed by the ultrasound and the foetal well-being is confirmed by the non-stress test. The attitude should be kept steady and fixed with the hands for some time after successful version. Transient bradycardia could be there due to minimal cord compressions but if it persists for more than 5 min then it warrants for immediate termination of pregnancy by caesarean section. Patient could be planned for induction of labour after assessing the bishop’s score or could be sent home if NST is reassuring, awaiting for spontaneous onset of labour. Many studies have proven that immediate induction of labour results in high chance of caesarean section due to failed induction [21]. Some clinicians try repeat attempt if the version fails or if there is reversion to breech on the subsequent visit. Second attempt can be tried under tocolytic effect if the first attempt was performed without the cover of uterine relaxant. Anti-D immunoglobulin should be given to the patient after the procedure if the patient is Rh negative. If the repeat version too fails, the patient has to be planned either for: • Elective caesarean section • Planned vaginal delivery Rodriguez et al. did a 10-year retrospective cohort study and proved the successful impact of ECV and subsequent planned vaginal breech delivery in 2015 in properly selected patients. They used intravenous (IV) ritodrine 30 min before version by continuous 200 μg infusion pump and used atosiban intravenously 0.9 mL bolus at least 2 min before starting version if someone had contraindication to rotodrine. NST was done for 60 min and patient was sent back home if no untoward incidence happened, just to repost if labour ensues. Many scientific societies (RCOG, ACOG) and Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) changed their guidelines and advocated the use of external cephalic version with vaginal breech delivery at term in well-selected patients [22]. In spite of this, many societies still do not promote ECV and their incidence of Lower Segment Caesarean Section (LSCS) is as high as 100%.

14 Elective Caesarean Section Breech deliveries are already associated with increased rate of neonatal morbidity irrespective of mode of delivery but as discussed before, after the Term Breech Trial, recommendations were established to offer the elective caesarean sections in primi breeches.

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Patient should be planned for elective caesarean section at 38 completed weeks as 1 in 10 patients can go in labour beyond 38 weeks and can come with premature rupture of membranes, nullifying the benefits of planned surgery offered to her. Especially in footling presentation, due to high risk of cord prolapse patient should be admitted and timely subjected to the surgery. Some studies have advocated caesarean section in preterm breech presentation, especially between 32 and 37 weeks, i.e. birth weight between 1.5 and 2.5 kg, as the foetal head is bigger than the foetal breech, which might lead to head entrapment during labour. Recently, FRABAT—FRAnkfurt Breech At Term—project has come up with a plethora of literature on vaginal breech deliveries to re-implement the vaginal deliveries in breech presentation. One of the studies—FRABAT prospective cohort study, by Lucas et  al. [23]—has compared the perinatal outcomes of vaginally intended breech deliveries between births out of frank breech position and incomplete/complete breech presentation: 884 women at term with a singleton in frank breech presentation and 284 women with incomplete or complete breech presentation. There were no differences in caesarean section rates, and short-term foetal morbidity was same irrespective of foetal leg posture. In vaginal deliveries the need to perform manual assistance was more in complete breech. Women should be informed about the risk of perinatal mortality of about 0.5/1000 with caesarean sections after 39 weeks as compared to 2/1000 with planned vaginal birth. Planned cephalic birth has nearly 1/1000 risk. Planned caesarean section at term has minimal increased risk of immediate complication in mother in comparison to planned vaginal birth, but the highest risk is with emergency section, which is needed in about 40% of patients planned for vaginal breech delivery. Hence proper counselling is very crucial in all patients while deciding the mode of delivery. The patient should also be counselled about the risk of repeat caesarean section and subsequent risk of morbidly adherent placenta with elective caesarean section. Kielland-Kaisen et al. [24] compared the maternal and neonatal outcomes after vaginal breech delivery of nulliparous (n  =  647) versus multiparous (n  =  399) women of singletons at term with favourable pelvic measurements. Neonatal morbidity and mortality was not significantly different in both groups. Significantly higher rates of caesarean during labour, maternal birth injury rates and use of epidural anaesthesia were found in the nulliparous group. It ruled out nulliparity as an exclusion criterion for intended vaginal breech birth at term, but the increased risk of caesarean section during labour should be discussed with the patient. Charlotte et al.–FRABAT prospective control trial also provided evidence that in post-dated pregnancy with breech presentation, elective caesarean section is not mandatory. The maternal and neonatal morbidity was not increased in post-dated pregnancy [23]. Royal College of Obstetricians have provided the set of indications for the elective caesarean section where vaginal breech delivery is deferred. 1. Footling presentation—highest risk of cord prolapse, about 15–20% as compared to 1.4–6% in extended breech. In cephalic version the risk is lowest from

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0.2 to 0.5%. The FRABAT study has proved no differences in the perinatal outcome in different foetal leg posture. 2. Hyperextended neck during labour—as it can damage the cervical spine during vaginal birth. 3. Estimated foetal weight more than 3.5 kg—FRABAT prospective cohort study compared the neonatal and maternal outcomes in newborns weighing >3.8 kg High weight group (HWG) and 10.5 cm in the obstetric conjugate diameter), with the estimated foetal weight ≤3800  g and the biparietal diameter (BPD) 30 min

1 h >30 min

The risk factors for abnormal labours are maternal or foetal and some are listed in Table 1. Besides these there are the poor uterine contractions due to maternal illness, stress, anxiety or variable response to oxytocin. Inadequate and inco-ordinate uterine action will not cause enough power to be able to effectively expel the foetus out of the uterus (Table 2).

1.5 Management The management is of the labour abnormality diagnosed and of the underlying cause when identified. As per ‘The obstetric consortium committee’ 2016 prolonged latent phase is not an indication for caesarean delivery. Moreover, in first stage of labour it recommends against caesarean delivery if labour is progressive but slow— a protraction disorder. It should be managed with observation, assessment of uterine activity and stimulation of contractions as needed. Caesarean for active-phase arrest should be reserved for women at or beyond 6 cm of dilation with ruptured membranes who fail to progress despite 4 hours of adequate uterine activity, or at least 6 h of oxytocin administration with inadequate contractions and no cervical change.

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The management of the protracted descent is by oxytocin if the cause is uterine inertia. If the cause is dehydration, patient should be hydrated. The arrest of descent is by reassessing the underlying cause and treating it first. A vaginal delivery is achieved after ruling out the foetal and maternal factors. The arrest of dilatation is also by correcting the underlying cause and then delivering by the safest route. In conditions that are unlikely to change, the caesarean section is wiser. The precipitate labour is difficult to always anticipate, but a good history of previous deliveries can avoid it from occurring in some cases. Following a precipitate labour, a careful inspection of the mother for injuries or haemorrhage is necessary, and corrective measures are needed as soon as possible. These include the arranging of blood, suturing of tears and checking the foetus for any complications.

References 1. Medbullets M. Abnormal labor—obstetrics—medbullets Step 2/3. n.d. Retrieved September 28, 2021, from https://step2.medbullets.com/obstetrics/121756/abnormal-­labor 2. Gill P, Henning JM, Van Hook JW. Abnormal labor. In: StatPearls. StatPearls Publishing; 2021. http://www.ncbi.nlm.nih.gov/books/NBK459260/. 3. Emedicine M.  Abnormal labor: background, pathophysiology, epidemiology. 2020. https:// emedicine.medscape.com/article/273053-­overview.

Abnormal Uterine Action Munjal Pandya and Janki Pandya

1 Introduction Uterus has three layers of muscular arrangements. Initiation of uterine contractions is one of the prime events for the process of labor to start. The pacemakers, as we know, are at both cornua, and the impulse travel downwards towards cervix, with gradual reduction in intensity. With transition from latent to active phase of labor, the intensity and duration of contraction increase and the interval between contractions get reduced. We commonly refer to 4 “P,” for the process of vaginal delivery; namely, Power (uterine contractions), Passage (Maternal pelvis), Passenger (fetus), Presentation of fetus. This chapter mainly focuses on abnormality in “Power,” that is abnormal uterine contractions, which can range from excessive to inadequate. Poor uterine tone is known as “Hypotonia,” and excessive one is known as “Hypertonia.” Most of the cases of abnormal uterine actions are seen in nulliparous as compared with multiparous, more so in elderly nulliparous. Incoordinate uterine action includes wide spectra, as follows: Spastic Lower Segment  Irregular, painful uterine contractions, high intra-uterine pressure in between contractions and slow cervical dilation may lead to fetal non-­ reassuring fetal heart sounds. Cesarean section after correcting dehydration, with antibiotic cover is the management. Generalized Tonic Uterine Contraction (Tetanic Contractions)  The condition is characterized by tetanic contractions of whole uterus, with no distinction left

M. Pandya (*) · J. Pandya Narendra Modi Medical College, Ahmedabad, Gujarat, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_16

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between upper and lower segment. May be result of obstructed labor, excessive rate of dose of oxytocin. Cesarean section should be performed for terminating such a pregnancy. Cervical Dystocia  Failure of cervix to dilate at the expected rate leads to cervical dystocia, which can be either functional (primary) organic (secondary). Cesarean section is to be offered for both the causes. Asymmetrical Uterine Contraction  It is the condition with incoordinate uterine contractions due to multiple pacemakers and desynchronized actions of uterus and cervix. Cesarean section needs to be offered. Colicky Uterus  Cesarean section needs to be offered in such cases where there is presence of painful uterine contractions with irritability of uterus. Constriction Ring  Physiological ring is more of transverse, due to localized tetanic contraction of uterus. It may lead to sudden fetal non-reassuring fetal heart sounds, and arrest in labor. Cesarean section would be the procedure of choice.

2 Hypotonic Labor Hypotonic uterus is one of the commonest reasons for primary cesarean section [1]. USA and UK had rates of 37 and 27.3%, respectively, thus, necessitating evaluation of indications of cesarean section. Such hypotonic labor is characterized by poor and inadequate uterine contractions in active phase of labor; they have no effect on cervical dilation, effacement and descent of fetus, leading to prolonged delivery. Etiology Hypotonic uterus may be due to following causes: • Overdistension of uterus due to various causes like macrosomic fetus, polyhydramnios, multifetal gestation • Malpresentation/malposition of fetus, leading to inadequate impact of “Passenger” on lower uterine segment • Overdistended urinary bladder or loaded bowel or fibroid leading to interruption in myometrial activity • Uterine hypoplasia and small uterus due to wide excision of fibroids, leading to uterine deformities • Prematurity, due to reduced oxytocin receptors • Maternal exhaustion, maternal anemia and inadequate doses of labor analgesia

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Pathophysiology Adequate uterine contractions are to be stamped when they are 3–4  in number within 10 min, each lasting for at least 40 s, with pressure of 30–50 mm Hg above resting uterine musculature tone. The duration of each contraction increases from around 30 to 90 s in later stages of active labor [2]. Transition from latent to active phase was thought to be at around 3–4  cm of cervical dilation earlier. As now we know that, “6 is new 4,” cervical dilation from 0 to 6 is included under “Latent Phase,” while progress from 6 cm onwards comes under heading of “Active Phase” of first stage of labor. Hypotonic labor is characterized as follows having diminished uterine musculature intensity 25 mm Hg, duration of uterine contraction - less than 20–30 s, good relaxation in between contraction, and increased interval between contractions. Number of contractions are less than 2–3 within 10 min. Clinical Features Less pain during contraction, less frequency of uterine contractions, increasing interval between contractions, and maternal exhaustions are common features. On examination, inadequate cervical dilation and slowing down of decent of presenting part of fetus are seen. Slow progression is known as “Protracted labor,” and absence of progress is known as “Arrest of labor.” Patient should be in active phase of labor to be diagnosed to have uterine dysfunction [3]. Protracted labor is diagnosed when there is cervical dilation slower than 1–2 cm/h; and arrested labor is defined as no cervical dilation for more than 6 h with inefficient uterine contraction [4]. One of the modalities in case of morbidly obese woman is internal pressure catheter, which measures pressure generated. Uterine action less than 200–250 MVU (Montevideo units) is considered inadequate uterine activity. Management Supportive management in form of proper counselling, thus reducing catecholamine release from anxiety, encouraging ambulation, emptying of urinary bladder, adequate hydration and pain relief; seems to assist vaginal delivery [5].

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Active measures in form of artificial rupture of membrane in active phase of labor followed by oxytocin infusion in dose of 5 units of oxytocin in 500 mL of Ringer Lactate infusion, starting with 10 drops/min, and titrating it to achieve adequate uterine action; dose must not exceed 30 milliunit/minute [6]. Artificial rupture of membrane followed by oxytocin infusion is much more effective than oxytocin infusion alone [7]. Operative vaginal delivery using forceps or ventouse may be performed if clinical condition permits, and cesarean section should be considered if all other attempts fail at vaginal delivery. Maternal exhaustion, uterine atony leading to postpartum hemorrhage may occur. Fetal distress may not occur in early labor. Do not ignore it even when cervix is fully or near fully dilated, for favoring vaginal delivery. Hypotonic uterine contractions are very responsive to oxytocin.

3 Hypertonic Dysfunction Obstructed labor leads to tonic uterine contractions, leading to Bandl’s pathological retraction ring. Uterus becomes hard and tender, and the ring would be visible running oblique over the uterus. Fetal non-reassuring heart sounds may be immediate sequel. Cesarean section needs to be performed.

4 Precipitate Labor Total duration of labor is less than 3 h, which majorly occurs in multipara, when there are stronger uterine contractions, small fetus, wider and roomy pelvis. Precipitate labor might lead to lacerations of vaginal tract, uterine inversion, postpartum hemorrhage and puerperal sepsis. There are increased chances of fetal intra-­ cranial hemorrhage, fetal asphyxia, injuries to fetus due to fall. Previous history of precipitate labor entails vigorous monitoring in this pregnancy and admission before she goes in labor. When she goes in labor, inhalation anesthesia in form of nitrous oxide and oxygen may be administered. Tocolytic agents can be tried to slow down the process of labor. Episiotomy helps in preventing lacerations of vaginal tract, as well as fetal intracranial hemorrhage.

References 1. Bernitz S, Oian P, Rolland R, et al. Oxytocin and dystocia as risk factors for adverse birth outcomes: a cohort of low risk nulliparous women. Midwifery. 2014;30(3):364–70. 2. Lindgren L.  The influence of uterine motility upon cervical dilation in labor. Am J Obstet Gynecol. 1973;117(4):530–6. 3. Oladapo OT, Diaz V, Bonet M, et al. Cervical dilation patterns of ‘low-risk’ women with spontaneous labour and normal perinatal outcomes: a systemic review. BJOG. 2018;125(8):944–54.

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4. Song CV, Berghella V, Wenstrom KD, et al. Preventing the first cesarean delivery: summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, and American College of Obstetricians and Gynecologists Workshop. Obstet Gynecol. 2012;120(5):1181–93. 5. Hofmeyr GJ, Kulier R. Hands/knees posture in late pregnancy or labour for fetal malposition (lateral or posterior). Cochrane Database Syst Rev. 2000;(2):CD001063. 6. Satin AJ, Leveno KJ, Sherman ML, et al. Factors affecting the dose response to oxytocin for labor stimulation. Am J Obstet Gynecl. 1992;166(4):1260–1. 7. Clark SL, Nageotte MP, Garite TJ, et al. Intrapartum management of category II fetal heart rate tracings: towards standardization of care. Am J Obstet Gynecol. 2013;209(2):89–97.

Part IV Third Stage Abnormalities

Postpartum Hemorrhage Krupa Shah, Rajshree D. Katke, and Sakina Y. Radiowala

1 Introduction Postpartum hemorrhage (PPH) is a frequent complication encountered following a delivery. The major issues related to PPH are mortality and long term morbidity. It is one of the leading causes of maternal mortality around the world, especially in developing countries. It is responsible for 20–30% of maternal death, and a majority of which occurs within 4  h of post-delivery [1]. Millennium Development Goal (MDG) 2030 is to reduce the maternal mortality ratio to 70, and prevention and management of PPH is a key step toward it. Morbidity associated with it is many, such as acute renal failure, acute hepatic failure, hypovolemic shock, DIC, transfusion related complications, pituitary necrosis, postpartum anemia and depression, etc. Hence, it is of utmost importance to timely recognize, quickly decide for the usage of available resources and apt management of PPH.

K. Shah (*) Department of Obstetrics and Gynecology, Manipal Academy of Higher Education, Manipal, Karnataka, India R. D. Katke Department of Obstetrics and Gynaecology, Grant Government Medical College and Sir JJ Group of Hospitals, Mumbai, India Cama and Albless Hospital, Mumbai, India S. Y. Radiowala Cama and Albless Hospital, Mumbai, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_17

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2 Definition and Types PPH is classically defined as blood loss of 500 ml following a vaginal delivery or 1000 ml following a cesarean delivery. If it happens within 24 h postpartum, which occurs in the majority of cases, it is termed early PPH (EPH) or primary PPH. The hemorrhage after 24 h of delivery until 6 weeks postpartum is termed as late PPH or secondary hemorrhage. Primary PPH is divided into mild/minor (500–1000  ml), moderate (1000–2000 ml), and severe (>2000 ml) category [2]. The Government of India (GOI) defines bleeding of >1000 ml blood loss as massive PPH [3]. This definition is of limited use as quantification of blood loss is not always possible, hence, PPH may be recognized qualitatively as any amount of blood loss resulting in signs and symptoms of hypovolemia within 24 h of delivery [3]. Symptoms considered here are tachycardia, sweating, palpitation, headache, tachypnoea, etc. This qualitative diagnosis is more important when there is hidden or internal bleeding following vaginal delivery (VD) or cesarean delivery (CD). Reduction of hemoglobin by 2 gram% is considered as undiagnosed abnormal blood loss [4]. Different society [2, 3, 5, 6] criteria for defining PPH are mentioned in Table 1. The average blood loss at delivery is 500–700 ml and blood loss of >1000 ml is a more useful definition of PPH as it corresponds to the 95th centile for blood loss associated with spontaneous vaginal delivery [7]. The incidence is increased over time due to increasing cesarean delivery (CD) and atonicity. Quantitative measurement suggests higher PPH incidence. The majority of PPH are of mild category. Incidence varies widely from 0.4% to 33% [4]. Alternative methods for defining and diagnosing PPH have been proposed which include change in hematocrit, rapidity of blood loss, and changes in vital signs, all of which are complicated by the urgent nature of the condition [1]. PPH is often classified as primary/immediate/early, occurring within 24  h of birth, or secondary/delayed/late, occurring more than 24  h post-birth to up to 6 weeks postpartum (Fig. 1). Hemorrhage in pregnancy is a serious life-threatening complication and is one of the leading causes of maternal deaths worldwide.

Table 1  Definition of PPH by different societies Organization World Health Organization [5]

American College of Obstetrics and Gynaecology [2] Royal College of Obstetrics and Gynaecology [6] Government Of India [3]

Definition Blood loss of >500 ml within 24 h of delivery Severe PPH: Blood loss > 1000 ml within the same timeframe Blood loss >1000 ml/blood loss accompanied by signs or symptoms of hypovolemia within 24 h of delivery Minor and major PPH: 500–1000 ml, and >1000 ml blood loss, respectively Major is further divided into moderate and severe PPH Similar to World Health Organization and any a small blood loss causing hemodynamic instability

Postpartum Hemorrhage ANTEPARTUM HAEMORRHAGE

Conception 22 weeks Foetal viability

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24 hours PRIMARY

6 weeks SECONDARY

POSTPARTUM HAEMORRHAGE

Fig. 1  Types of hemorrhage

3 Causes of Postpartum Hemorrhage In the entire duration of pregnancy, there is an increase in maternal blood volume by approximately 50% (from 4 to 6 l). The plasma volume increases more than the total RBC volume, leading to a relative dilution and fall in the hemoglobin concentration and hematocrit value. This increase in blood volume is of utmost importance to compensate for the perfusion demands of the low-resistance uteroplacental unit and to provide a reserve for the blood loss that occurs at delivery [3]. Risk factors for PPH may present antenatally or intrapartum. Care plans must be modified as and when risk factors arise. Some women are at greater risk for postpartum hemorrhage than others. Conditions that may increase the risk include: • • • • • • • • • •

Placental abruption Placenta previa Overdistended uterus due to polyhydramnios, macrosomia, or multiple pregnancy Pregnancy induced hypertension Grand multipara Prolonged labor Infection Obesity Use of forceps or vacuum-assisted delivery Asian or Hispanic ethnic background There is increased risk of severe postpartum hemorrhage in women conceiving with assisted reproductive technology both in twin and singleton pregnancies. Minimization of modifiable antenatal risks is required to prevent postpartum hemorrhage. Such measures include: 1. Investigation and diagnosis of antenatal anemia and its appropriate treatment as this may reduce the morbidity associated with PPH [2]. 2. Active management of third stage of labor using uterotonic administration (preferably oxytocin) immediately upon delivery of the baby, early cord clamping and cutting, and gentle cord traction with uterine countertraction when the uterus is well contracted (i.e., Brandt-Andrews maneuver) [4].

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3.1 Causes of Primary PPH As a way of remembering the causes of PPH, several sources have suggested using the “4 T’s” as a mnemonic: tone, tissue, trauma, and thrombosis [5]. Box 1 Etiopathogenesis of PPH • Tone (uterine atony) • Trauma (laceration/rupture) • Tissue (retained products) • Thrombin (coagulopathy)

70% 20% 10% 1%

Further search for etiology is done by looking and assessing for Ts. The most common cause is atonicity (70%) and then trauma (20%), tissue (10%), and thrombin (1%). Mixed variety is also found.

3.1.1 Tone Uterine atony due to failure of contraction and retraction of myometrial muscle fibers is the most common cause of postpartum hemorrhage which results in severe and rapid hemorrhage and hypovolemic shock. Overdistension of the uterus, either absolute or relative, is a major risk factor for atony. Overdistension of the uterus can be caused by multifetal gestation, fetal macrosomia, polyhydramnios, or fetal abnormality (e.g., severe hydrocephalus); a uterine structural abnormality; or a failure to deliver the placenta or distension with blood before or after placental delivery. Prolonged labor or rapid forceful precipitate labor can also result in poor myometrial contraction from fatigue. Certain drugs also inhibit contractions such as halogenated anesthetic agents, nitrates, nonsteroidal anti-inflammatory drugs, magnesium sulfate, beta-sympathomimetics, and nifedipine. Other causes include placental implantation site in the lower uterine segment, bacterial toxins (e.g., chorioamnionitis, endomyometritis, septicemia), hypoxia due to hypoperfusion or Couvelaire uterus in abruptio placentae, and hypothermia due to massive resuscitation or prolonged uterine exteriorization. 3.1.2 Tissue Uterine contraction and retraction leads to detachment and expulsion of the placenta. Complete detachment and expulsion of the placenta allows continued retraction and occlusion of blood vessels. Placental abnormalities like succenturiate lobe increase the chances of retained placental tissue. Following delivery of the placenta and when minimal bleeding is present, the placenta should be inspected for evidence of fetal vessels coursing to the placental edge and abruptly ending at a tear in the membranes. Such a finding suggests a retained succenturiate lobe.

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Placenta accreta syndrome is a leading cause of antepartum hemorrhage (vaginal bleeding) affecting approximately 0.4–0.5% of all pregnancies. Failure of complete separation of the placenta occurs in placenta accreta and its variants. A serious sequalae of this syndrome results in maternal complications postpartum such as adherent placenta, postpartum hemorrhage (PPH), and shock, which may also necessitate stepwise devascularization and peripartum hysterectomy [6]. This condition should be considered possible whenever the placenta is implanted over a previous uterine scar, especially if associated with placenta previa. The placenta is more likely to be retained at extreme preterm gestations (especially 4kg baby)

• Asian ethnicity • Anaemia • Induction • BMI >35 • Prolonged labour • Age

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3.3 Management of PPH PPH is recognized as brisk red bleeding. Blood loss has to be assessed quantitatively by various tools. The estimation of blood loss is generally visual, but it has a high possibility of under-estimation (up to 50%). The objective way of estimating of blood loss is by weighing dry and wet drapes, mops, towels, and tampons. The weight difference of unused and soaked material will provide an estimation of blood loss in a better way than visual method. Volumetric assessment is blood collection in a basin, which is most practical. Specially designed bags are also available to estimate the blood loss. The modified Brecher’s formula also helps in evaluation [4]. Regardless of etiology, the obstetrician would summon senior and skilled doctors and personnel for help and start resuscitation. Anytime, if mild PPH is turning to severe PPH, then teamwork by the multidisciplinary team of a senior obstetrician, physician, anesthetist, intensivist, and transfusion therapist/hematologist is crucial. Senior theater staff, runner, and laboratory staff are critical in the management of severe PPH. The goals of treatment are 1. Prevention and correction of hypovolemia 2. Prevention of hypoxia 3. Search and correction of the cause of PPH 4. Reversal/treatment of coagulopathy The management needs the identification of an etiology and resuscitation, which should go hand in hand (Table 4).

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Postpartum Hemorrhage Table 4  Stages of PPH, shock, and treatment/assessment of severity Stage and amount of blood loss Mild PPH (10–15% blood volume loss) 500–1000 ml

Shock stage Compensated stage

Signs and symptoms Palpitations, light headedness, dizziness, slight tachycardia BP: Normal/>90 mm of Hg

Management Initial steps:

• Initiate red alert • Ensure IV access: 16 G/18 G • Fundal massage, vital signs monitoring • Oxygen 2–3 l by mask • Catheterization Medications: • IM or IV Syntocinon (5 U), IM Syntometrine • IV infusion of oxytocin (10–40 U, initially 500 ml in 10 min, then 125 ml/h, then add second-line uterotonics like methyl ergometrine, carboprost, misoprostol, etc.) • Crystalloids 500 ml–1 l Actions • Manage the cause atony/trauma • Blood loss assessment • Inform blood bank for 2–4 cross-match blood • Keep facility ready to transfer to tertiary care hospital • Documentation of events and inform patient party • If cesarean delivery, consider stepwise devascularization and compression stitches (continued)

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Table 4 (continued) Stage and amount of blood loss Severe PPH (25–35% of blood volume loss, 1500– 2000 ml)

Continued Severe PPH>2–3 l (35–45% blood volume loss)

Shock stage Stage 2 or moderate shock

Stage 3 or severe shock

Signs and symptoms Weak pulse volume Restlessness, confusion, pallor, oliguria, tachycardia 120–140 beats/min, cool, and clammy skin BP: 70–80 mm of Hg

Air hunger, very lethargic, severely decreased urine output, collapse, pulse >140 beats/ min BP: 50–70 mm of Hg

Management Initial steps: • Activate multidisciplinary team and Ob emergency

• Move to operative room • Communicate and plan Medications: • Continue medications as suggested above • Increase IV oxytocin 80 U/500 ml at rate of 125 ml/h • Tranexa 1-g IV over 10 min, repeat later • Antibiotics Action • Initiate massive blood transfusion protocol • Consider obstetric hysterectomy if conservative procedures are not successful • Laboratory parameters: coagulation profile, blood gas analysis, calcium, and potassium every 15 min • Monitor TEG/ROTEM • Keep patient warm and maintain saturation >95% As above

TEG thromboelastogram, ROTEM rotational thromboelastometry

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4 Identification of PPH It is of utmost importance that clinical signs and symptoms should be included in the assessment of PPH. As visual estimation often underestimates blood loss. Clinical signs and symptoms of hypovolemia should be included in the assessment of PPH. However, due to the physiological increase in circulating blood volume during pregnancy, the signs of hypovolemic shock may be masked. In pregnancy, pulse and blood pressure are usually maintained in the normal range until blood loss exceeds 1000 ml; tachycardia, tachypnoea, and a slight recordable fall in systolic blood pressure occur with blood loss of 1000–1500 ml. A systolic blood pressure below 80  mmHg, associated with worsening tachycardia, tachypnoea, and altered mental state, usually indicates a PPH in excess of 1500 ml [2]. Here we will discuss all four “Ts” as the cause of PPH and its specific management.

4.1 Uterine Atonicity It is the most common cause of PPH; however, a thorough clinical assessment is required to rule out other causes of PPH. Atonicity makes the uterus to be felt soft and boggy, resulting in fresh heavy bleeding. The following interventions are used to stop bleeding.

4.1.1 Pharmacological Agents Oxytocin infusion is the first line of therapy. Second-line uterotonic are ergots, carboprost, misoprostol, and carbetocin. Doses and compilations are mentioned in Table 5. Table 5  Pharmacological agents for management of PPH Drugs Oxytocin

Onset of action Onset 2–3 min Lasts up to15–20 min

Ergots

Onset 2–7 min Lasts 2–4 h

Carboprost (15 methyl PGF2 alpha) Misoprostol

Onset 1–2 min Lasts 15–20 min

Carbetocin

Tranexamic acid Dinoprostone

Onset 3–5 min Lasts up to 75 min Onset of action within 2 min, last for 1 h Onset of action within minutes Onset of action 10–15 min, last for few hours

Dosage and compilation 20–40 units in 500 ml normal saline, 500 ml in 10 min, then 250 ml/h or 10 units IM/5U IV (if already administered in third stage of labor, can be repeated) Methylergometrine 0.2 mg or ergometrine 0.5 mg or ergonovine, 0.25 mg IM/IV, can be injected at the interval of 15 min for five injections 0.25 mg IM, repeated 15 min up to eight doses or 0.5 mg IM incrementally up to 3 mg or 0.25–0.5 mg intramyometrial 800–1000 μg rectally

100 μg IV bolus, can be given IM

1 g (in 10 mL) is infused over 10–20 min. If bleeding persists, repeat after 30 min 20 mg vaginally or rectally at 2 h interval

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Tranexamic acid helps to reduce the blood loss by almost 20%, it is recommended when other uterotonic fails or PPH is due to trauma. Though it is more helpful for coagulation disturbance. The treatment of patients with PPH has two major components: (1) resuscitation and management of obstetric hemorrhage and, possibly, hypovolemic shock and (2) identification and management of the underlying causes of the hemorrhage. The following protocol must be applied in management of primary postpartum hemorrhage [2]: Call for help

A and B – assess airway and breathing

C – evaluate circulation

Position the patient flat

Keep the woman warm using appropriate available measures

Transfuse blood as soon as possible, if clinically required

Until blood is available, infuse up to 3.5 l of warmed clear fluids, initially 2 l of warmed isotonic crystalloid. Further fluid resuscitation can continue with additional isotonic crystalloid or colloid. Hydroxyethyl starch should not be used. Transfusion of FFP should be done, if no hemostatic results are available and bleeding is continuing. After 4 units of RBCs, FFP should be infused at a dose of 12–15 ml/kg until hemostatic test results are known. If no hemostatic tests are available, early FFP should be considered for conditions with a suspected coagulopathy, such as placental abruption or amniotic fluid embolism, or where detection of PPH has been delayed. If PT/APTT is more than 1.5 times normal and hemorrhage is ongoing, volumes of FFP in excess of 15 ml/kg are likely to be needed to correct coagulopathy [2]. The management of PPH can be further classified into mechanical, pharmacological, and surgical methods.

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Interventions

Uterotonics

Haemostatic drugs

Surgical

Compression techniques

Oxytocin

Tranexamic acid

Hemostatic brace sutures

Uterine tamponade

Carbetocin

Recombinant activated factor VII

Stepwise uterine devascularization

Bimanual Compression

Selective Arterial Embolization

Uterine massage

Ergometrine Prostaglandins

Misoprostol Carboprost

The following mechanical methods can be used to control hemorrhage: 1. Palpate the uterine fundus and rub it to stimulate contractions (“rubbing up the fundus”). 2. Ensure that the bladder is empty. Insert a Foleys catheter which will additionally help in output monitoring. 3. Intrauterine tamponade: Tamponade using various types of hydrostatic balloon catheter has superseded uterine packing for the control of atonic PPH. These catheters include Foley catheter, Bakri balloon, Sengstaken–Blakemore esophageal catheter, and Shivkars condom catheter. The urological Rusch balloon has been also been described as preferable by virtue of larger capacity, ease of use, and low cost. Intrauterine tamponade has been shown to be an effective method for controlling bleeding in cases of atonic PPH in resource poor settings. Pharmacological Measures First line therapy

Uterotonic agents

Second line drugs

First line drugs

Oxytocin Carbetocin

Misoprostol

Methylergometrine

Carboprostol

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• Oxytocin 5 IU by slow intravenous injection (may have repeat dose) • Ergometrine 0.5 mg by slow intravenous or intramuscular injection (contraindicated in women with hypertension) • Oxytocin infusion (40 IU in 500 ml isotonic crystalloids at 125 ml/h) unless fluid restriction is necessary • Carboprost 0.25 mg by intramuscular injection repeated at intervals of not less than 15  min to a maximum of eight doses (use with caution in women with asthma) or intramyometrial (Fig. 2) • Misoprostol 800 μg sublingually. • rFVIIa (NovoSeven, Novo Nordisk, Bagsværd, Denmark) is an expensive product that is licensed for the treatment of bleeding episodes in patients with specific inherited bleeding disorders. It has been used primarily in the management of uncontrolled hemorrhage in the trauma setting. It reduces blood loss through enhancement of tissue factor-dependent coagulation. Its effectiveness is markedly diminished by hypothermia, acidosis, and low platelets, so effective resuscitation toward normal physiology is a prerequisite of its use. In December 2018, WHO issued new recommendations on uterotonics for PPH prevention (Table 6). 15 Oxytocin (10 IU, intravenously or intramuscularly) remains the recommended uterotonic of choice for all births. In settings where oxytocin is unavailable (or its quality cannot be guaranteed), the use of other injectable uterotonics (carbetocin, or if appropriate ergometrine/methylergometrine or oxytocin and ergometrine fixed-dose combination) or oral misoprostol is recommended for

Intra - myometrial uterotonics in a flabby uterus

Fig. 2  This image shows intramyometrial injection of prostaglandin F2-alpha in a case of uterine atony following cesarean section as a method to control postpartum hemorrhage. (Image Courtesy: Dr Rajashree D Katke)

100 mg i.v. or i.m.

0.2–0.5 mg oral, i.m., or i.v.

1 ml i.m. (combination of 5 IU oxytocin plus 0.5 mg ergometrine) 400–600 mg oral, sl, rectal 250 mg i.m.

Carbetocin

Methylergometrine

Syntometrine

Carboprost

Misoprostol

Dose and route 10 IU i.m. or 5–10 IU by slow i.v. injection

Drug Oxytocin

Table 6  Pharmacokinetics of various ecbolics

20 min

3–5 min

2–3 min

5–15 min after oral

2 min

Onset of action 2–3 min

3 h

75 min

3 h

2–4 h after i.v. injection, 6–120 min after i.m. injection 2–5 min after i.m., instantaneous after iv 2–4 h

Duration of action 15–30 min

Shivering, pyrexia, nausea, vomiting and diarrhea Nausea, vomiting, diarrhea, headaches, hypertension and bronchial asthma

Same as oxytocin and ergometrine

Headache, nausea, vomiting, dizziness, hypertension, coronary artery spasm, intracerebral hemorrhage

Side effects Hypotension, myocardial ischemia, arrhythmias, nausea, vomiting, headache, flushing, and release of atrial and brain natriuretic Nausea, vomiting, abdominal pain, hypotension, headache, chilling and pyrexia

Cardiac and pulmonary disease

Unknown

Hypertension, heart disease, retained placenta, preeclampsia, and eclampsia Same as oxytocin and ergometrine

Uterine, vaginal or cervical rupture

Contraindications Unknown

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the prevention of PPH. In those settings where skilled health personnel are not present to administer injectable uterotonics, the administration of misoprostol (400 or 600 μg orally) by community healthcare workers and lay health workers is recommended for the prevention of PPH [15]. Are skilled health personnel who can administer injectable uterotonics available?

No

Trained community health workers and lay health workers can administer misoprostol (400 µg or 600 µg PO)

Yes Is exytocin available?

OR No

Yes

Is oxytocin of sufficient quality?

Heat-stable carbetocin (100 µg, IM/IV), in contexts where its cost is comparable to other effective uterotonics.

Oxytocin is not available, or its quality cannot be guaranteed No

Ergometrine / methylergometrine (200 µg, IM/IV), in contexts where hypertensive disorders can be safety excluded prior to its use. OR Fixed-dose combination of oxytocin and ergometrine, in contexts where hypertensive disorders can be safely excluded prior to its use.

Yes

Use oxytocin (10 IU, IV or IM)

OR Misoprostol (400 µg or 600 µg PO)

The main therapeutic goals of the management of massive blood loss are to maintain [2]: • • • • •

Hb greater than 8 g/dl Platelet count greater than 50 × 103/cumm Prothrombin time (PT) less than 1.5 times normal Activated partial thromboplastin time (APTT) less than 1.5 times normal Fibrinogen greater than 2 g/l.

If pharmacological measures fail to control the hemorrhage, surgical interventions should be initiated sooner rather than later. Intrauterine balloon tamponade is an appropriate first-line “surgical” intervention for most women where uterine atony is the only or main cause of hemorrhage. Conservative surgical interventions may be attempted as second line. Resort to hysterectomy sooner rather than later (especially in cases of placenta accreta or uterine rupture).

4.1.2 Mechanical Methods 1. Uterine massage: Transabdominal uterine massage preferably following emptying bladder is a part of the management of third stage of labor. Sustained external massage is considered as the first-line therapy of uterine atony. 2. Bimanual compression: It is performed by one hand in the vagina pushing against the body of uterus, and the abdominal hand compresses the fundus from above. This causes apposition of walls of uterus and reduces bleeding.

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4.1.3 Theater The procedures mentioned below are performed in a stepwise manner. It needs clinical expertise and the availability of facility. 1. Balloon tamponade: Intrauterine balloon tamponade is a conservative procedure for the treatment of atony even at a primary health center, where a medical officer is available. Foley catheter in resource poor centers (Fig. 3) or Bakri balloon, Rusch balloon, or Sengstaken-Blakemore esophageal catheter is available commercially. It needs anesthesia preferably and is effective in 80–84% of cases. The prerequisite is uterus should be empty. Here, the device is inflated by warm fluid until a uterine cavity is obliterated and bleeding stops (100–500  ml of fluid). Observation for bleeding through the cervix and catheter tip should be done. It can be kept in place up to 24 h and once the patient’s condition becomes stable, it is removed [16, 17]. It is effective when used early before coagulopathy sets in. If it does not work, the next preferred modality is compression stitches. 2. Vacuum tamponade: It is used as an alternate to balloon tamponade in PPH following vaginal delivery. Here, a low level of vacuum induces uterine myometrial contractions. Paniker’s cannula, Jada system, or suction cannula is used to create vacuum and reduce surface area, the collapse of a wall, thus minimize bleeding. It can be kept up to 24 h. It is effective in 87% of cases associated with atony [18]. Hemostatic/compression stitches: Surgical techniques: 1. Hemostatic brace sutures: 2. B-Lynch and colleagues in 1997 described this surgical technique for atonic uterus. In this, pair of vertical brace sutures is secured about the uterus with no 2 Fig. 3  How to make balloon tamponade using condom and Foley catheter

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Fig. 4  B-Lynch sutures



chromic catgut. This suture works by compressing the anterior and posterior wall placental bed, thus reducing the uterine blood loss, the objective of this surgical technique is to compress uterus without occluding uterine arteries [12]. The success rate of this suture is 86.4% in avoiding obstetric hysterectomy and thus this suture is widely recommended for atonic PPH [13]. B-lynch suture, Haymen (modified B-lynch), and Cho stitches have an effectiveness of up to 91% [10, 16, 18]. B-lynch suture is preferred following LSCS.  Here, vertical brace sutures are placed around the uterus as mentioned in Fig. 4. The prerequisite is obstetrician has to make sure that bleeding stops with compression of the uterine wall with two hands. After a vaginal delivery, if medical method and massage fail, then Haymen stitches are taken as mentioned. (a) In 2002, Hayman et al. described a modified compression suture which does not require hysterotomy. Double vertical compression sutures have proved effective in treating PPH due to atony and placenta previa. This may have a dual action of reducing uterine blood flow and compressing the bleeding surface. Cho sutures (Fig. 5): Compression stitches are simple and safe, do not require special training. Sometimes, uterine necrosis infection can occur. Cervico-isthmic and pereira stitch are also preferred to control PPH at some centers [9]. These stitches are taken with catgut or with vicryl. A needle transfixes the uterus from anterior to posterior (point a) and then from posterior to anterior (point b). The same is done (points c and d) to approximate the anterior and

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Fig. 5  Cho stitches

posterior uterine walls in a “square” manner. In an atonic uterus, four to five square sutures should be made. If the bleeding point is evident, suturing should be performed to compress the bleeding site. The purpose of the technique is to approximate the uterine walls until no space is left in the uterine cavity. In a study by Ikeda A no case of atonic postpartum hemorrhage required arterial embolization or laparotomy when contrast extravasation was not present in the arterial phase but when the contrast agent was leaking in the arterial phase arterial embolization was required in 50%, and in 36% cases, direct compression of the bleeding point with an intrauterine balloon could establish hemostasis. Compression sutures or hysterectomy is not n­ ecessary in the absence of PRACE (postpartum hemorrhage resistant to treatment showing arterial contrast extravasation on dynamic CT scan). CT has limited availability and is not suitable in hemodynamically unstable patients (E Kondoh) and they have advised to rethink about compression sutures as actually very few cases need it and target should be on single arterial bleeding point. Xueqin Shi found circular suture of the uterine serosa and myometrium at the placental attachment site effective in controlling refractory PPH and postoperative complications were also minimal. 3. Stepwise devascularization: Uterus receives 90% of blood supply from the uterine artery. Ligation of uterine artery reduces myometrial flow and perfusion pressure. It helps to reduce bleeding. Stepwise uterine devascularization describes the successive ligation of [14] (a) one uterine artery (b) both uterine arteries (c) one ovarian artery (d) both ovarian arteries Stepwise uterine devascularization should be the first-line conservative surgical treatment to control PPH. High uterine ligation is above the bladder peritoneum reflection and low uterine ligation is below it, which needs blad-

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der mobilization. This is a first line of surgical procedure in about 60–70% of PPH cases, having effectiveness up to 84% [17]. It is quite safe procedure without many complications. Stepwise devascularization involves ligation of utero-ovarian vessels anastomosis. Clamp across the utero-ovarian ligament is a quick and simple means of reducing blood loss. It is an interim procedure. Uterine tourniquet: Urinary catheter or Penrose drain is placed as low as possible in the lower uterine segment, avoiding urinary bladder. This will reduce bleeding and if needed second and third catheter are also placed as a tourniquet. This is a temporary method to reduce blood loss. Once the patient becomes hemodynamically stable, further definitive procedure is carried out and a tourniquet is removed. Bilateral ligation of internal iliac artery: Internal iliac artery ligation should be considered after stepwise devascularization has failed to achieve adequate hemostasis. It needs expertise and challenging technique in presence of a gravid uterus, low transverse incision, and with ongoing hemorrhage. It reduces blood flow by 50% and pulse pressure by 85% and converts the arterial system in to the venous system, thereby helps in clot formation [17]. However, retrograde filling of a vessel has been reported leading to compromised results. Again, with placenta percreta, where there is an extensive collateral supply, results are suboptimal. This may help to avoid an emergency hysterectomy. The anterior division of internal iliac artery is ligated (4–5 cm away from its origin) (Fig. 6). The risk associated with the procedure is ureter injury and iliac vein injury. Women who underwent internal iliac artery ligation as the first-line surgical intervention had a hysterectomy rate of around 39%. Studies have shown that subsequent fertility and pregnancy outcomes are not impaired [2]. 4. If a patient is hemodynamically unstable, along with resuscitative measures, below-mentioned procedures are carried out either as a temporary method until shifting to higher centers or as definitive measures are carried out. (a) External aortic compression: This emergency maneuver is proposed to reduce severe PPH. Here, the aorta is compressed just above the umbilicus by the firm pressure of a closed fist against the spine (Fig. 5). It is done just above the sacral promontory or below the renal artery origin. This maneuver shuts off the blood supply of the uterus. This is recommended in life-­ threatening severe hemorrhage, where there is an imminent threat of exsanguination. Check for the femoral pulse and if it is not palpable, then compression is adequate. Maintain the pressure till bleeding stops, other care is initiated, or she reaches the operative theater. Another option is an intra-aortic balloon catheter just below the renal artery and it should be deflated intermittently to prevent ischemia of limb and colon complications. Selective arterial embolization: Uterine or internal iliac artery embolization can be achieved at centers where interventional radiologists and equipment facilities are available (Fig.  7). This is a relatively newer technique

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Fig. 6  Internal iliac artery ligation

Fig. 7  Selective arterial embolization



which may be considered as a prophylactic means of preventing postpartum hemorrhage in suspected high risk cases such as placenta accreta pre-­ operative to reduce blood loss. The logistics of performing arterial occlusion or embolization may pose a challenge where the equipment or an interventional radiologist may not be available. (b) It can be planned pre-operatively, as in cases of placenta accreta. It would help reducing bleeding during obstetric hysterectomy or during conservative management in the placenta accrete spectrum. It can be done post-­procedure,

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i.e., in cases of persistent bleeding following laparotomy, where a patient is deteriorating despite of uterine or internal iliac artery ligation to control PPH.  It can be asked intra-operatively if facilities are available. This ­procedure has first a diagnostic angiogram and then an embolization of bleeder. It has a high success rate of 90–97% [16]. (c) Uterine packing: Not used widely nowadays. This technique fell out of favor decades back. Here, few yards of gauze are placed inside the uterine cavity from one cornual end to other and packing it back and forth. It can be kept up to 24 h. The risks associated are infection and concealed hemorrhage. (d) Obstetric hysterectomy: Hysterectomy Early recourse to hysterectomy is recommended, especially where bleeding is associated with placenta accreta or uterine rupture [14]. Hysterectomy should not be delayed until the woman is in extremis or while less definitive procedures with which the surgeon has little experience are attempted. (e) In cases of persistent torrential bleeding, placenta accrete, or rupture uterus, Obstetric hysterectomy is a definitive treatment. It is needed in 1.1–2.3% of EPH cases. It can be a total or a subtotal procedure, depending on local conditions and the doctor’s preference. It is associated with urinary tract injury [19, 20]. (f) Pelvic packing: It is performed in case of persistent bleeding following obstetric hysterectomy, in case of the lack of selective arterial embolization, for the patient to transport to a tertiary care center. It is a useful procedure in case of broad ligament hematoma, retroperitoneal hematoma, laceration difficult to repair due to location or friability of tissue, and bleeding-related coagulopathy while factors being replaced.

4.2 Trauma Laceration and hematoma are the reasons for traumatic PPH after birth in 20% of cases. Hence, through examination of genital tract-cervix, vagina, and perineum is performed to recognize. Primary management is surgical repair and hemostasis [21]. Laceration of cervix/cervical tear, vaginal and para-urethral laceration are commonly found in mild PPH, pressure pack on bleeding area and repair at labor room or operative theater is recommended. Sometimes, an episiotomy can be the reason for excessive blood loss, hence timely and indicated ones only should be performed. If a patient has normal vaginal bleeding but with hypotension and tachycardia, then consider for an intra-abdominal source of bleeding that is the ruptured uterus, broad ligament hematoma, or surgical cause like liver rupture, splenic rupture, or splenic artery accident, etc. Hematoma results in vital signs which are out of proportion to blood loss. Vulval and vaginal hematomas are accompanied by pain at the vulvo-vaginal region. Patients with small hematoma can be managed conservatively, with icepack and analgesics. Large hematomas, expanding hematoma, hematoma with signs of volume loss despite fluid replacement, require incision and drainage under anesthesia. Surgery steps involve irrigation and removal of clot,

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ligation of bleeder, and layer closure or figure of eight stitches at the hematoma site. It is generally followed by a pressure pack for few hours. The need for blood transfusion depends on the hemodynamic features. Uterine rupture is another reason for intrapartum and postpartum hemorrhage. It generally happens with a scarred uterus but can happen in an unscarred uterus. The prime signs of uterine rupture are fetal bradycardia, abdominal sharp pain, vaginal bleeding, superficial palpation of fetal parts, cessation of uterine contraction, etc. Induction or augmentation increases the risk of uterine rupture, especially with a scarred uterus. Treatment is laparotomy and control of bleeding. Sometimes, it may require an obstetric hysterectomy. Uterine inversion can also lead to signs and symptoms of shock, though it is rare. The mismanaged third stage of labor, placental adherence, fundal attachment of placenta, and inappropriate traction on the cord can result in uterine inversion. Here, the uterine inner surface is exposed outside and it appears as bluish-gray mass at the vagina. All efforts to replenish the uterus quickly have to be made. The management involves uterine relaxation and reposition of the uterus, preferably under anesthesia. The removal of placenta is recommended only after repositioning uterus if it is attached. It is generally carried out under general anesthesia. Terbutaline, magnesium sulfate, or nitroglycerine is used to achieve good relaxation if needed. Once reposition is achieved, uterotonics are infused to prevent a recurrence.

4.3 Tissue Tissue in form of retained placenta, placental cotyledons/fragments, membrane, and blood clot are an important cause for PPH, as it interferes with tonic uterine contraction. In the presence of tissue, the uterus cannot contract effectively and lead to PPH. If the placenta has been delivered check it for missing cotyledons. Think of succenturiate placenta, the segment of bipartite placenta even if placenta appears complete. Ultrasound of the uterus would help to find retained bits of placenta. Uterine exploration and either manual removal or surgical evacuation are required to remove the small retained bits. The adherent placenta can be delivered by control cord traction, crede maneuver and remember, the longer the time taken for the placental delivery, the more is the bleeding. If the placenta does not deliver within 30 min of delivery, it is a retained placenta. It needs manual removal of a whole placenta/part of placenta. Here, gloved fingers would try to get a separation plane between placenta and uterus, starting from the edge of placenta. If the plane along the whole or at a focal area of placenta is not achieved by such a blunt action, it is taken as a completely or partially adherent placenta. The adherent placenta is known for dangerous hemorrhage. High suspicion of placenta accreta complex (in previous cesarean cases, previous history of accreta, elderly age and parity, placenta previa cases) would help to allow pre-­ procedure preparation for uterine artery embolism in selected cases. Treatment is an obstetric hysterectomy or leaving placenta and following up with methotrexate tablets/injection.

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4.4 Thrombin/Coagulation Disorders Coagulation defect is responsible for nearly 1% of PPH. Apart from the congenital factor deficiency, coagulation defect or DIC may result in PPH.  Here, bleeding would not come under control with usual methods. There might be bleeding from the puncture site or oozing from the wound. Bedside tests like bleeding time increase and blood does not get clot within 5–10 min. Tests like platelet count (PC), platelet activity, prothrombin time (PT), activated prothrombin time (APTT), fibrinogen, fibrinogen degradation products (FDP), and d-dimer studies are asked. “Point of care” testing is important in the management of PPH. The reasons for coagulation problems are mentioned in Table  7. Cryoprecipitate or fibrinogen concentrate is important when the fibrinogen is 50,000 8. PT and APTT 35 °C 11. No hypocalcemia • A patient would be given 2–5 l of oxygen by face mask in mild cases, high flow oxygen up to 15 l/min in ongoing severe cases, and ventilation as per the requirements as suggested by anesthetist if impaired consciousness. Table 7  Reasons for coagulopathy Inherited coagulopathy Idiopathic thrombocytopenia Thrombotic thrombocytopenia Von Willebrand disease Hemophilia

Acquired Amniotic fluid embolism Placental abruption Severe preeclampsia HELLP syndrome Sepsis Intrauterine death DIC secondary to abruption, excessive blood loss, and clotting factor dilution

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• Intravenous warm fluid in form of normal saline and ringer lactate through wide-bore needle. In mild PPH, similar or double of the amount of blood loss and moderate PPH, 2–3 times of the blood loss is infused. Colloid becomes an important component of fluid resuscitation in moderate to severe PPH.  Generally, 3.5  l (liter) crystalloids and 1.5  l of colloids are advised (complications of colloids: acute kidney injury, pruritus, >1–1.5 l infusion interfere with hemostasis). Meta-analysis of Cochrane library favored the use of crystalloid concerning to mortality [22]. • Elevation of legs to help with venous return and hence improve hypotension. • Bladder drainage through Foley’s catheter would improve uterine tonicity and keep the assessment of urine output. • Antibiotics: generally broad-spectrum and anaerobic coverage should be provided where intervention is necessary. • Blood and blood products should be started as soon as available. O negative blood should be started while waiting for type-specific blood. • Massive transfusion protocols are established to reduce the chance of dilutional coagulopathy (DIC) and quick recovery. This protocol recommends four bags of FFP and one bag of platelets with 4–6 PCV [23]. • The multidisciplinary team is essential to manage cases of massive PPH. The mnemonic “hemostasis” conveys the logical sequence of management of PPH. It means ask for help (H), assess vitals and resuscitate (A), etiology search, and ensure uterotonics and blood (E), massage uterus (M), oxytocin and uterotonics (O), shift to theater (S), tamponade of uterus (T), apply compression stitches (A), stepwise devascularization (S), interventional radiology/internal iliac ligation (I), subtotal/total hysterectomy (S) [24].

5 Laboratory Assessment A single value is not useful for assessment of bleeding and its severity, serial measurement are quite specific. Mild PPH, complete blood count (CBC), and DIC panel (PT, APTT, serum fibrinogen, FDP d-dimer) are requested. Arterial blood gas analysis, serum lactate, calcium, and potassium are added for severe ongoing bleeding. Thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are point of care testing available at higher centers. It is performed every 30–60 min depending on stability and improvement of patient condition. Lactate 4.5kg). Inversionnnn i Inversionnnn fundal attachment of the placenta and fundal pressure in relaxed uterus

Uterine Inversion

Primiparity, Women with Connective tissue disorders (Marfans syndrome or EhlersDanlos Syndrome) History of Inversion In previous pregnancy. Mostly Unpredictable without any Risk factor.

2.1 Etiopathogenesis: May Be Spontaneous or Iatrogenic 1. Fundal portion of the uterine wall tends to prolapse through the dilated cervix or indents forward 2. Iatrogenic inversion—excessive cord traction when the uterus is relaxed and fundal pressure (Credé maneuver) during the third stage of labor [1]. 3. Simultaneous downward traction on the fundus resulting in worsening of the uterine inversion 4. Localized inertia of placental site over the fundus which turns inside when suddenly intra-abdominal pressure is raised due to forceful coughing, sneezing, or bearing down effort.

3 Clinical Presentation Patient presents with precedent delivery followed by sudden onset of vaginal bleeding leading to hemodynamic instability of the patient. Usually, the shock has been considered disproportionate to blood loss. The cause of which is possibly parasympathetic stimulation caused by the stretching of tissues. Careful evaluation for the

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need of blood transfusion should be made because blood loss is usually massive and may be underestimated. The other symptoms are mainly severe lower abdominal pain with a strong bearing down sensation. Patient may not be able to complain due to severe shock. It may occur before or after placental detachment [1].

4 Signs and Symptoms Acute uterine inversion should be suspected when a patient in immediate puerperium complains of severe lower abdominal pain with a “bearing down sensation.” There is also presence of vaginal bleeding with shock (out of proportion to blood loss) and/or urinary retention.

5 Clinical Signs Clinical examination itself can diagnose inversion. Lack of palpation of a normally positioned fundus is the key finding. There is absence of uterine fundus (cup-like defect) from its expected periumbilical position. On bimanual examination, the inverted fundus may be palpated in the lower uterine segment or inside the vagina, Inverted uterus may be seen protruding through vagina reaching the perineum. Role of ultrasound and magnetic resonance is only done when patient is stable and usually not essential.

6 Differential Diagnosis Those clinical situations that cause a lump protruding through the vagina are: 1. Myomatous necrosed polyp Physical and ultrasonographic examination help to distinguish the two disorders: the fundus is usually normal in case of polyp, whereas with uterine inversion the fundus is absent on abdominal palpation. Cervical rim may also be palpated in case of necrosed polyp. 2. Prolapse uterus: The cervical os is visible in case of prolapse. Other conditions leading to post-partum collapse include: 1. Atonic post-partum hemorrhage 2. Neurogenic collapse 3. Post-partum collapse due to cardiac cause 4. Retained placenta without inversion 5. Coagulopathy 6. Amniotic fluid embolism

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7 Treatment Once the diagnosis of uterine inversion is made, immediate intervention is required to prevent maternal morbidity. Treatment of shock and correction of inversion goes hand in hand. Oxytocin drip should be immediately stopped. Uterine relaxing drugs like inhalational halogens may be administered by anesthetists. Tocolytic drugs like magnesium sulfate or beta agonists or nitroglycerine may be used in cases of tense constriction ring.

Management Of Shock(neurogenic & Hypovolemic)

Correction of Inversion

1.Call for help, assistants, senior Obstetician and Anesthetists 2. Correction of Hypovolemia by large bore cannula . Sample obtained for Blood transuion and crystalloids rushed till blood comes. Broad spectrum Antibiotics given

Goal is to replace the uterine fundus to its correct position as early as possible Wearing long gloves. Prompt intervention is critical since the lower uterine segment and cervix will contract over time and create a constriction ring, making manual replacement progressively more dificult. Placenta should not be removed

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Steps of Correction of Inversion 1. If the Placenta is separated , manual repositioning of uterus is done by pushing the fundus of uterus by palm and inger,ist of hand in the direction of long axis of vagina (igure3)

If the placenta is attached,(Figure 5) NO attempt should be made to separate e eparate e the placenta from the inverted uterus. Magnesium sulfate or beta-mimetic ta a mime mimetic m e 2.

and nitroglycerine can be used for relaxation

3. O'sullevans Method of Hydrostatic reduction (igure 2) is performed ed when manual repositioning fails.Warmed sterile saline is infused into the vagina. The clinician’s hand or a silicone ventouse cup is used as a luid retainer to generate intravaginal hydrostatic pressure whilst the introitus is sealed and resultant correction of the inversion.Fluid bag should be elevated about 100 to 150 ds may ds ay cm above the vagina to obtain suficient pressure. Two to three liters of luids be required. Hydrojet is ideal for obtaining the desired pressure. Complications-infection, failure of the procedure, and saline embolus Hydrostatic Reduction (O’Sullivan technique):

Once uterus is in position, uterotonics should be started to prevent recurrence Once it is felt hard, placental removal should be done, uterotonic agents are administered to maintain myometrial contraction and reduce the risk of hemorrhage. 1 to 2 20 200 0 An oxytocin infusion (20 to 40 units in 1 liter of crystalloid infused at 150 mL per hour) is titrated to keep the uterus contracted. Other options,, include: includee 0mcg 0 Misoprostol 800 to 1000 micrograms vaginally and/or carboprost250mcg

Management of Placenta Removal of the placenta needs to be awaited until the uterus has been replaced and contracted. Removing the placenta before replacing the uterus increases blood loss, which may be severe (9). Careful exploration of uterus and removal of any remaining bits of placenta should be removed. Ensure there is no uterine/cervical trauma. If haemorrhagic shock, needs prompt treatment and resuscitation. Watch out for Post-Partum Haemorrhage

If all attempts to replace the uterus fails , surgical correction is opted.

Surgical correction of Uterine Inversion. If these procedures are performed, then pregnancies in the future will require a cesarean delivery.

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Fig. 1  Inversion uterus

Fig. 2  Hydrostatic method

1. Huntington Repair At laparotomy gradually pulling on the round ligaments to bring the uterus to its position (Fig.  1).The fundal dimple formed by the inversion is identified (Fig. 2).

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Allis or Babcock clamp is placed on each round ligament entering the dimple, approximately 2 cm deep in the dimple. If the round ligaments cannot be identified, the adjacent myometrium may be clamped. Gentle pulling on the clamps exerts upward traction on the inverted fundus [7]. Clamping in 2 cm increments followed by traction is repeated until the inversion is corrected. An assistant places a hand in the vagina and applies upward digital pressure on the fundus. 2. Haultain procedures An incision (approximately 1.5 in. in length) is given on the posterior surface of the uterus to transect the constriction ring, thereby increasing the size of the previously constricted area [8, 9]. This surgical release of the constriction ring would allow manual reduction of the uterine inversion (Fig. 3). Manual reduction may be performed through the vagina or through the myometrial incision. Surgeon tries to reach below the fundus through the myometrial incision and then exerts pressure on the fundus to reduce the inversion. The incision is repaired after correction of the inversion. Cervical incisions with manual uterine repositioning. Fig. 3  Inversion of uterus abdominal approach for correction

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If the placenta is not separated from the uterus, then a hysterectomy may be necessary. Laparoscopic-assisted repositioning [10–12] can be done.

8

Postnatal Care

First 24 h need close monitoring as there is chance of PPH. Oxytocin drip is continued after correction of the uterine inversion. It reduces the risk of hemorrhage and prevents re-inversion. Counseling the patient and her family are very important step. Debriefing is essential for explaining the prognosis, need for blood transfusions, its complications and recurrence. Record keeping and documentation should be proper.

9 Complications [1] 1. Post-partum hemorrhage (37.7%) 2. Blood transfusion (22.4%) 3. Need for laparotomy (6.0%) 4. Hysterectomy (2.8%) 5. Hypotension (2.1%) leading to multiorgan damage 6. Shock (1.3%) leading to Sheehan’s syndrome 7. Amniotic fluid embolism 8. Death

10 Recurrence The risk of recurrence of uterine inversion in a future pregnancy is not known but some studies showed there is no recurrence in subsequent pregnancies [2].

11 Prevention Appropriate management of third stage. Cord traction should not be applied until the signs of placental separation are apparent and uterus becomes hard.

References 1. Coad SL, Dahlgren LS, Hutcheon JA. Risks and consequences of puerperal uterine inversion in the United States, 2004 through 2013. Am J Obstet Gynecol. 2017;217:377.e1. 2. Baskett TF. Acute uterine inversion: a review of 40 cases. J Obstet Gynaecol Can. 2002;24:953.

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3. Witteveen T, van Stralen G, Zwart J, van Roosmalen J.  Puerperal uterine inversion in the Netherlands: a nationwide cohort study. Acta Obstet Gynecol Scand. 2013;92:334. 4. Pauleta JR, Rodrigues R, Melo MA, Graça LM.  Ultrasonographic diagnosis of incomplete uterine inversion. Ultrasound Obstet Gynecol. 2010;36:260. 5. https://www.ncbi.nlm.nih.gov/books/NBK525971/#_ncbi_dlg_citbx_NBK525971; https:// www.ncbi.nlm.nih.gov/books/NBK525971/#:~:text=Uterine%20Inversion,%3B%20 Angesh%20Thakur. 6. Lipitz S, Frenkel Y.  Puerperal inversion of the uterus. Eur J Obstet Gynecol Reprod Biol. 1988;27:271. 7. Huntington JL, Irving FC, Kellogg FS. Abdominal reposition in acute inversion of the puerperal uterus. Am J Obstet Gynecol. 1928;15:34. 8. Huntington JL. Acute inversion of the uterus. Boston Med Surg J. 1921;184:376. 9. Haultain FW.  Abdominal hysterotomy for chronic uterine inversion. Proc R Soc Med. 1908;1:279. 10. Haultain FWN. Abdominal hysterotomy for chronic uterine inversion: a record of three cases. Edinb Med J. 1908;1:528. 11. Vijayaraghavan R, Sujatha Y. Acute postpartum uterine inversion with haemorrhagic shock: laparoscopic reduction: a new method of management? BJOG. 2006;113:1100. 12. Sardeshpande NS, Sawant RM, Sardeshpande SN, Sabnis SD.  Laparoscopic correction of chronic uterine inversion. J Minim Invasive Gynecol. 2009;16:646.

Part V Placental Abnormalities

Retained Placenta Archana Kumari and Ritu Raj

1 Introduction Retained placenta occurs in around 1–3% of deliveries [1]. When the placenta fails to separate spontaneously within a stipulated time or is delivered incompletely with a part of it still in utero, the diagnosis of retained placenta is almost certain [2–4]. It is one of the known abnormalities associated with ‘the four Ts’ (tone, tissue, trauma and thrombin) of PPH [2, 3]. Retained placenta in toto or its part can cause significant bleeding and might require urgent surgical intervention. It is identified to be the second most prevalent cause of postpartum haemorrhage (PPH) after uterine atonicity [5, 6]. It is therefore one of the common causes of morbidity in modern obstetrics [5, 7]. The morbidities associated with retained placenta can be mitigated by early appreciation of the associated risk factors and its timely management.

2 Incidence of Retained Placenta When awaiting spontaneous placental separation as in expectant management, the placenta usually delivers within 10–20 min. On the other hand, active management of third stage of labour (AMTSL) enables placenta to deliver within 5–10 min. The probability of placental delivery within 15, 30 and 60 min are 90%, 96% and 98% respectively [8]. The incidence of retained placentas has increased over time, although the reason for the same is unclear [9]. The time at which one declares placenta retained and takes active steps for its removal depends on the presence or absence of haemorrhage, haemodynamic status of patient, availability of an experienced obstetrician, anaesthetist and emergency OT. A. Kumari (*) · R. Raj Department of Obstetrics and Gynaecology, AIIMS, New Delhi, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_19

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3 Pathophysiology Normal placentation starts once the blastocyst gets implanted into the endometrium. With the effect of progesterone and estrogen in early pregnancy, the endometrium prepares itself for implantation by developing into decidua which in turn is invaded by the blastocyst. The blastocyst has an outer cell layer which further divides and develops into the chorionic membrane. In the chorionic membrane, the outer layer of cytotrophoblastic cells proliferate and transform into multinucleated syncytiotrophoblast which in turn form the placental villi. These villi are responsible for foeto– maternal interchange. With the delivery of the baby, the combined effect of hormonal cascade and uterine contractions facilitate separation of the foetal membranes from uterine surface and thereby expulsion of the placenta [10]. In general, the following pathophysiologies are often hypothesized to predispose to retained placenta: • First, if there are poor uterine contractions as in an atonic uterus, the placenta might fail to separate and expel within the stipulated time frame [3, 11, 12]. • Second, if the placenta is abnormally adherent to uterine wall as in placenta accreta spectrum (PAS), the placenta fails to separate from its uterine attachment. • Finally, a placenta which has already separated may be trapped or incarcerated in the uterus if cervix closes before delivery of the placenta [3, 11–13]. • Sometimes, miscellaneous causes like pre-eclampsia and infection have been associated with retained placenta, hypothesis being placental hypo-perfusion, although little is known about its specific mechanism [12, 14].

4 Risk Factors Attributed for Retained Placenta • If there is a history of retained placenta in a previous pregnancy, the recurrence risk for the same is around 25% [4]. • Poor myometrial contractility (causes placenta adherence): –– Preterm labour (a retained placenta is noted with around 25% of all deliveries at 25 weeks compared with only 3% of deliveries at term) –– Uterine fibroids –– Labour induction or need for oxytocin augmentation –– Pre-eclampsia and stillbirth • Disrupted myometrial–placenta interface (causes partial accreta) –– Previous miscarriage and abortion –– Uterine anomaly (e.g. Bicornuate uterus) –– Uterine scar (previous CS, myomectomy, hysteroscopic surgery, curettage) • Premature contraction of the lower segment (causes a trapped placenta), e.g. use of IV ergometrine for PPH prophylaxis

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5 Diagnosis of Retained Placenta Diagnosis is mostly made by clinical discretion depending on the time elapsed since birth. Even today many clinicians consider manual removal as the only successful therapeutic option for retained placenta, but how long to delay the procedure remains an important question to be addressed. A more nuanced approach is using careful clinical examination and/or ultrasound to distinguish between the various types of retained placenta [8]. A Trapped placenta is diagnosed when there is failure of placenta expulsion despite definitive signs of its separation from the uterus. In these cases, the placental edge may be palpated vaginally through a narrow cervical os. The ultrasound can elicit an empty uterine cavity and the placenta is seen bunched up in the lower part of the uterus (Fig. 1). With Placenta accreta, there are no signs of placental separation and the placenta can sometimes be felt in the soft fundus of the uterus, which is distended and wide. The ultrasound often elicits that the myometrium is wide and contracted in all areas except the site of placental attachment, where it is very thin or even invisible. Placenta adherens fall between these two extremes. Here, commonly there are signs of placental separation with a firm uterine fundus. The ultrasound images may also be confusing—the placenta may look detached like a trapped placenta, but some of the placentae can still be seen in the uterine cavity. The diagnosis is usually made while attempting manual removal of placenta. If the entire placenta can be separated from its uterine attachment with a clear plane of separation, the diagnosis of placenta adherens is certain while failure to appreciate a definite plane of separation, points towards focal invasion of myometrium as in focal placenta accreta. a

b

Fig. 1 (a) This patient had retained placenta with cord hanging from the vagina. (b) A bedside ultrasound image of retained placenta with * mark indicating the placenta of the same patient

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6 Management (WHO Recommendation) [15] • Call for help. Alert the senior obstetrician and the maternity team without any delay. • 2 wide bore IV cannulas are placed and blood samples are sent for cross-­ matching, urgent haemogram, coagulation profile and arrangement of blood and blood products. • Meanwhile, adequate fluid resuscitation should be done by crystalloids followed by colloids if situation warrants. • The bladder is emptied and catheterized if necessary as full bladder hinders delivery of the placenta. • If the retained placenta occurred despite AMTSL performed initially, an attempt to deliver the placenta by controlled cord traction (CCT) can be made. This should preferably be aided with maternal effort. Sometimes there is only minimal or no bleeding with retained placenta. • Note: The risk of uterine inversion should always be kept in mind while attempting CCT which is more with forceful traction with or without fundal pressure. • If the above measures fail and there is no excessive bleeding, the above step can be repeated after administering intramuscular (IM)/intravenous (IV) of an additional dose of 10 units of oxytocin. Alternatively, oxytocin with saline can be injected in the intraumbilical vein to facilitate expulsion of placenta. (The recommendation is weak. The unpublished RELEASE trial and other comparative studies does not prove its superiority in significantly reducing the need for manual removal of placenta) [16, 17]. • If still the placenta couldn’t be delivered and the patient is bleeding excessively or her clinical signs and symptoms are deteriorating, the clinician should raise the red flag sign. A senior/experienced obstetrician should intervene and without any undue delay proceed with manual removal of placenta. The clinical signs and symptoms are more important compared to peripartum blood loss as the latter is assessed by visual estimation which is often inaccurate. • Note: –– The patient and her attendant should be appropriately communicated about the situation and sequelae like need for hysterectomy should be explained as a life-saving procedure if the placenta fails to separate as in adherent placenta or PPH couldn’t be controlled by medical methods. –– The procedure should be undertaken by or in the presence of a team of experienced obstetrician and anaesthetist. –– A single shot of injectable prophylactic antibiotics should be considered before or at the time of procedure as per the hospital protocol [18, 19]. –– Adequate amount of blood and blood products should be arranged preferably before attempting the procedure but this should not delay the procedure in a woman with worsening haemodynamic status. • A bedside clotting test can be done at per clinician’s discretion to check the coagulation profile if unusual excessive bleeding is noted. If after 7  minutes, there is no formation of a clot or a soft-clot forms which breaks down easily suggests coagulopathy.

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• Standard antibiotics regimen should be given as per local protocol, if the history or examination is suggestive of an infection. These could be fever (high grade or low grade, continuous or intermittent), foul smelling vaginal discharge or the placental bits, uterine tenderness etc. Retained Placental Fragments  If one or more pieces or bits of placenta are retained, the uterus fails to contract effectively. This can be confirmed by properly examining the placenta. The placental fragments can be felt inside the uterus digitally and removed. Digital exploration of the uterus to be done similar to manual removal of placenta explained later in the chapter. Occasionally retained placental fragments do not manifest as excessive vaginal bleeding. Any uterine manipulation to remove the retained placental bits warrants a single dose of prophylactic antibiotics. • Ergometrine is known to cause tetanic uterine contraction. If used as a substitute or in addition to oxytocin, it can further delay expulsion of placenta. Hence, it is not at all recommended for the management of retained placenta. Even ­Prostaglandin E2 alpha (dinoprostone or sulprostone) is not approved for the same due to lack of enough evidences for its use [20].

7 Manual Removal of Placenta (Figs.  2, 3 and 4) 7.1 Indication 1. If the placenta fails to expel within 30 minutes of birth of the baby and is associated with excessive bleeding or worsening of haemodynamic staus of woman. 2. If excessive bleeding is not there, a trial with an additional dose of uterotonics in supplementation with CCT can be given for another 30  minutes provided the woman is stable throughout. If this fails or the woman deteriorates, manual removal of placenta should be done without delay [21, 22].

7.2 Who Should Perform the Procedure? An experienced obstetrician preferably under anaesthesia and it should be performed in OT with proper aseptic measures in place.

7.3 Procedure [21] • The informed consent is taken from the patient and her attendant after explaining her procedure in simple terms. Sometimes, a verbal consent can suffice ­considering the urgency of situation. When the woman is being cared for, a companion of her choice can be allowed who can provide emotional support to her.

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Fig. 2  Demonstrating the introduction of dominant (right) hand along the cord which is held by non-dominant hand (left hand) Fig. 3  Demonstrating the use of non-dominant (left) hand to support the fundus while attempting manual removal of placenta

• General care principles are reviewed and an IV infusion is started. • A single dose of prophylactic antibiotic should be given if not already given. The antibiotics of choice are ampicillin 2 g IV—or cefazolin 1 g IV. • The procedure can be performed under IV sedation like slow IV injection of morphine and diazepam or preferably under general anaesthesia. • If the woman is in haemorrhagic shock, the medications that can affect the mental status (i.e. narcotic pain medication and sedatives) to be avoided.

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Fig. 4  Demonstrating how the placenta is removed by grasping it in toto by the hand inside the uterus while a continuous counter-traction is maintained in an opposite direction by the hand supporting the fundus

• The bladder is emptied and catheterized if needed. • The clamp holding the umbilical cord is caught hold of and the cord is pulled gently with non-dominant hand to align it parallel to the ground while the dominant hand is inserted into the uterus through the vagina in a cup fashion (Fig. 2). • The cord is now left and the non-dominant hand is placed over the abdomen to support the uterine fundus. In order to prevent uterine inversion, a sustained counter-traction is applied over the uterine fundus while attempting removal of placenta by the dominant hand (Fig. 3). Note: If at any time during the procedure uterine inversion occurs, the repositioning of the uterus needs to be done immediately by an experienced obstetrician. • The placental edge is identified by gently moving the fingers of the hand laterally inside the uterus. • A hand can be directly introduced into the uterine cavity if the cord is very short or has avulsed by any means while the other hand is used to support the fundus. By gently moving the fingers of hand all around the placenta inside the uterine cavity, a plane of separation is delineated to detach the placenta from uterine wall (Fig. 4). • The entire placenta is gently detached from the adjacent uterine walls by swift movement of the fingers along with the plane of cleavage all around the placenta. • Once the entire placenta is detached, the walls of the uterine cavity are further palpated to ensure that complete placenta has been removed. The obstetrician slowly withdraws her/his hand bringing the placenta along. During the entire procedure, a counter-traction is to be maintained on the fundus in the opposite direction of the hand retrieving the placenta. • If the placenta fails to detach completely along the plane of cleavage despite the movement of fingers along with this plane, the fragments of placenta are removed by piecemeal preferably under ultrasound guidance (USG). If the placenta is completely adherent, i.e. a definite cleavage plane cannot be delineated, placenta accreta should be suspected and a decision for laparotomy and possible subtotal hysterectomy can be taken depending on the clinical scenario and set-up available.

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• After the placenta has been brought out, oxytocin infusion is continued in the standard dose, i.e. 10 units in 500 mL IV fluid at the rate of 60 drops/min, to combat atonic PPH which is very likely after manual removal of placenta. • Simultaneously, the assistant should massage the uterine fundus to encourage uterine contraction. • If heavy bleeding continues and there is no contra-indication for ergometrine or carboprost, the same should be considered in appropriate dose as for atonic PPH. • Meanwhile, the placental surface is thoroughly examined to ensure its completeness. If any portion of placenta is found missing, further exploration of uterine cavity is warranted to remove the missing portions. This can be better done under USG. • After ensuring good uterine tone, proceed with fourth stage of labour, i.e. careful examination of cervix, vagina and perineum to identify any tears. The same is repaired to ensure thorough haemostasis.

8 Problems • If a long time (hours or days) has passed since the delivery of the baby and there is formation of definite constriction ring, the entire hand cannot be inserted into the uterine cavity which is required for removing the placenta manually. • In this scenario, the placental fragments can be removed digitally using two fingers or by using instruments like ovum forceps or a wide curette preferably under USG.

9 Post-procedure Highlights • The woman is closely observed by a responsible team member until the effect of IV sedation/anaesthesia is there. • Vitals (pulse, blood pressure, respiration, hydration and urine output) are closely monitored immediately after the procedure. For initial 2 h, monitoring is done every 15 min, which is then followed by every 30 min for the succeeding four to 6 h or till the time the woman is stable. • Simultaneously, the uterine tone is assessed to ensure that uterus remains contracted. • Local examination is done to check for any bleeding or excessive lochia. • Infusion of IV fluids continued. • Blood and blood products are transfused as necessary. • The procedure and the post-procedure orders including the medications are legibly documented. Antibiotics should be administered as per hospital protocol. • The woman and her attendant should be briefed about the procedure and why it was done. • Hospitalization is needed for at least 24 h after childbirth to provide optimum postnatal care.

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References 1. Nicola CP, Daniela AC. Retained placenta after delivery: risk factors and management. Int J Women’s Health. 2019;11:527–34. 2. Dombrowski MP, Bottoms SF, Saleh AA, Hurd WW, Romero R. Third stage of labor: analysis of duration and clinical practice. Am J Obstet Gynecol. 1995;172(4 Pt 1):1279–84. 3. Combs CA, Murphy EL, Laros RK. Factors associated with postpartum hemorrhage with vaginal birth. Obstet Gynecol. 1991;77(1):69–76. 4. Nikolajsen S, Løkkegaard ECL, Bergholt T.  Reoccurrence of retained placenta at vaginal delivery: an observational study. Acta Obstet Gynecol Scand. 2013;92(4):421–5. 5. Endler M, Grünewald C, Saltvedt S. Epidemiology of retained placenta: oxytocin as an independent risk factor. Obstet Gynecol. 2012;119(4):801–9. 6. Bateman BT, Berman MF, Riley LE, Leffert LR. The epidemiology of postpartum hemorrhage in a large, nationwide sample of deliveries. Anesth Analg. 2010;110(5):1368–73. 7. American College of Obstetricians and Gynecologists. ACOG practice bulletin: clinical management guidelines for obstetrician-gynecologists number 76, October 2006: postpartum hemorrhage. Obstet Gynecol. 2006;108(4):1039–47. 8. Weeks AD, Baskett TF, Sabaratnam A, Michael SR. Chapter 35 – Retained placenta. In: Munro Kerr’s operative obstetrics. 13th ed; 2021. p. 234–8. 9. Cheung WM, Hawkes A, Ibish S, Weeks AD. The retained placenta: historical and geographical rate variations. Obstet Gynaecol. 2011;31(1):37–42. 10. Kraus FT, Redline RW, Gersell DJ, Nelson DM, Dicke JM.  Placental pathology. American Registry of Pathology in collaboration with the Armed Forces Institute of Pathology. Atlas Nontumor Pathol. 2004;1:10–6. 11. Urner F, Zimmermann R, Kraft A. Manual removal of the placenta after vaginal delivery: an unsolved problem in obstetrics. J Pregnancy. 2014;2014:274651. 12. Greenbaum S, Wainstock T, Dukler D, Leron E, Erez O. Underlying mechanisms of retained placenta: evidence from a populationbased cohort study. Eur J Obstet Gynecol Reprod Biol. 2017;216:12–7. 13. Kramer MS, Berg C, Abenhaim H, et al. Incidence, risk factors and temporal trends in severe postpartum hemmorhage. Am J Obstet Gynecol. 2013;209(5):449.e1–7. 14. Endler M, Saltvedt S, Cnattingius S, Stephansson O, Wikström A-K.  Retained placenta is associated with pre-eclampsia, stillbirth, giving birth to a small-for-gestational-age infant, and spontaneous preterm birth: a national register-based study. BJOG Int J Obstet Gynaecol. 2014;121(12):1462–70. 15. Managing complications in pregnancy and childbirth: a guide for midwives and doctors, 2nd ed. Geneva: World Health Organization; 2017. Licence: CC BY-NC-SA 3.0 IGO. 16. Carroli G, Bergel E. Umbilical vein injection for management of retained placenta. Cochrane Database Syst Rev. 2001;(4):CD001337. 17. The Release Trial: a randomised trial of umbilical vein oxytocin versus placebo for the treatment of retained placenta. http://isrctn.org/ISRCTN13204258. 18. Chongsomchai C, Lumbiganon P, Laopaiboon M. Prophylactic antibiotics for manual removal of retained placenta in vaginal birth. Cochrane Database Syst Rev. 2006;(2):CD004904. 19. Criscuolo JL, et  al. The value of antibiotic prophylaxis during intrauterine procedures during vaginal delivery. A comparative study of 500 patients. J Gynecol Obstet Biol Reprod. 1990;19(7):909–18. 20. Van Beekhuizen HJ, et al. Sulprostone reduces the need for the manual removal of the placenta in patients with retained placenta: a randomized controlled trial. Am J Obstet Gynecol. 2006;194(2):446–50. 21. WHO guidelines for the management of postpartum haemorrhage and retained placenta. 2009. ISBN 978-92-4-159851-4. 22. Leduc D, Senikas V, Lalonde AB, Ballerman C, Biringer A, Delaney M, et  al. Clinical Practice Obstetrics Committee; Society of Obstetricians and Gynaecologists of Canada. Activemanagement of the third stage of labour: prevention and treatment of postpartum hemorrhage. SOGC Clinical Practice Guideline No. 235. J Obstet Gynaecol Can. 2009;31:980–93.

Placenta Accreta Spectrum Sruthi Bhaskaran and A. G. Radhika

1 Introduction The term Placenta Accreta Spectrum (PAS) disorder describes breach of the decidua basalis and penetration of trophoblastic tissue into the uterine myometrium, the uterine serosa or even the pelvic organs. It includes the entire spectrum starting from abnormal adherence of placenta to uterine wall (placenta accreta) and abnormal invasion into myometrium or adjacent organs (placenta increta and placenta percreta) [1]. Placenta accreta is a histopathological term first described in 1937 by obstetrician Frederick C.  Irving and pathologist Arthur T.  Hertig [2]. Caesarean deliveries, which are a major and most common risk factor, have increased worldwide, resulting in an increase in PAS disorders [3]. The prevalence of this condition around the world varies greatly and most often lacks histopathological confirmation. In a systematic review published in 2019 the pooled prevalence of PAS was 0.17% (range 0.01–1.1%) [4]. There is a greater risk to the foetus as a result of iatrogenic prematurity, while increased risk of obstetric haemorrhage and surgical complications affects the women with PAS. As much as 60% of mothers are reported to suffer from morbidity; mortality rates reported in the past ranged from 7% to 10% [5]. However, the improvement in prenatal diagnosis and management of this condition in multidisciplinary centres has reduced the mortality [6–8]. The risk of mortality is likely to decline further as clinicians gain experience in screening for high-risk patients and developing new surgical techniques. Prenatal diagnosis improves maternal outcome by enabling planned delivery in referral centres with a multidisciplinary care team and adequate resources and

S. Bhaskaran · A. G. Radhika (*) Department of Obstetrics and Gynecology, UCMS & GTB Hospital, New Delhi, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_20

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equipment [9, 10]. When the diagnosis is missed prior to surgery, the operating surgeon is faced with an extremely demanding situation. The use of standardized protocol and terminology for both the clinical diagnosis and histopathological confirmation of PAS disorders is essential to obtaining more accurate epidemiological data.

2 Pathophysiology A number of theories have been proposed to explain its pathophysiology, including one that proposes that a defect at the endometrium–myometrium interface causes abnormal decidualization at the uterine scar site [11]. The decidua is scanty or absent in these cases, particularly in the area of scarring and the physiological line of cleavage through the decidual spongy layer is lacking. This favours preferential attachment of the blastocyst to the scar tissue and trophoblasts implanting in an avascular scar may invade deeper into the uterine wall. Lack of normal vasculature in underlying tissues and low oxygen tensions induces a prolonged maintenance of the invasive trophoblast, and hence a prolonged invasion [12]. This theory is supported by the observation that majority of patients with PAS have a history of previous caesarean delivery, uterine curettage and/or myomectomy. Nevertheless, this theory cannot explain why this condition is found among primiparas (though rarely) without uterine surgery or instrumentation. Additionally, the factors that influence the extent of pathologic invasion (e.g. accreta versus percreta) are not well understood. Pathologists have classified three subtypes of trophoblast invasions into the myometrium based on their depth of invasion: (1) superficial placenta accreta (also called placenta accreta, vera or adherenta), where the villi attach directly to the surface of the myometrium without invading it; (2) placenta increta, where the villi penetrate deeply into the myometrium up to the serosa and (3) placenta percreta, where the invasive villous tissue reaches and penetrates through the uterine serosa [11, 13].

2.1 Risk Factors and Epidemiology There are several risk factors for development of PAS. Theoretically, any primary uterine anomaly or secondary damage to the uterine wall structure can lead to PAS disorders (Table 1). 1. Caesarean scar: This is one of the major risk factors for PAS. The risk is seen to increase with the number of caesareans. According to studies, the rate of PAS increases from 0.3% after one caesarean to 6.74% following five or more [15].

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Placenta Accreta Spectrum Table 1  Uterine pathologies associated with PAS [1, 2, 11, 13, 14] Classification Uterine surgery (involving the endometrial cavity)

Endometrial scarring without surgery

Uterine anomalies and other miscellaneous conditions

Uterine pathology Caesarean section Dilatation and curettage Myomectomy Endometrial resection Asherman’s syndrome Hysteroscopic adhesiolysis Cornual resection of ectopic pregnancy After in vitro fertilization (IVF) procedures Uterine artery embolization Manual removal of placenta Endometritis After chemotherapy or radiotherapy Intrauterine device Previous accreta Bicornuate uterus Adenomyosis Submucous myoma Myotonic dystrophy

Women who had a primary elective caesarean delivery without labour were more likely to develop a PAS disorder (OR 3.0, 95% CI 1.5–6.1) [16]. There is limited evidence on suture materials used for uterine closure, single-layer versus double-layer uterine incision closure, and locked versus unlocked single-layer closures with subsequent development of placenta accrete [17]. 2. Placenta previa: This is the single most important risk factor for PAS. The risk of PAS with placenta previa without previous caesarean is about 3%. The risk increases with prior caesarean deliveries, 3%, 11%, 40%, 61% and 67% for first, second, third, fourth and five or more caesareans, respectively [18]. 3. Surgical procedures such as uterine curettage, manual removal of the placenta, postpartum endometritis and, more recently, hysteroscopic surgery, endometrial ablation and uterine artery embolization, cause damage to the integrity of the uterine lining. These procedures are associated with PAS disorders in subsequent pregnancies [11, 13, 19]. PAS disorders have also been reported in women without prior uterine surgery, but with uterine pathology such as bicornuate uterus, adenomyosis, submucous fibroids and myotonic dystrophy. However, they are not considered as major risk factors for PAS disorders. The entry into the uterine cavity at myomectomy and the size of the myometrial scar may affect the risk for PAS disorders in subsequent pregnancies, though this risk is low [20, 21].

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4. Additional risk factors include (a) Advanced maternal age. This association is most likely due to confounding factors such as multiparity, risk of previa and the risks of prior uterine surgery. (b) The Nordic Obstetric Surveillance Study, which investigated severe obstetric complications between 2009 and 2012 found OR of 3.1 for PAS disorders (absolute risk: 8.2 per 10,000) in pregnancies resulting from in vitro fertilization (IVF) [18]. A recent meta-analysis of cohort studies including 161,370 pregnancies resulting from Assisted Reproductive Techniques (ART) compared with 2,280,241 spontaneous singleton pregnancies found no difference in the relative risk (RR) for PAS disorders. More data are required to determine the impact of ART on PAS disorders and other placental and cord anomalies [22]. 5. It is likely that caesarean scar pregnancy in the first trimester represents a continuum of the same disease. The high risk of invasive placentation and/or major placenta previa later in pregnancy should be explained to women, along with the option to terminate the pregnancy [23].

3 Diagnosis Antenatal diagnosis of placenta accreta spectrum is highly desirable as outcomes can be optimized when delivery occurs at well-equipped facility, before the onset of labour or bleeding [9, 10, 24]. Most women with PAS remain asymptomatic. So, it is important to keep a high index of suspicion in women with above-mentioned risk factors and screen them for PAS. The primary diagnostic modality for antenatal diagnosis of PAS is ultrasonography with Colour Doppler Imaging (CDI) [25, 26]. In literature, numerous ultrasound guideline (USG) signs have been reported, each described with varying levels of sensitivity and specificity for diagnosis of PAS.

3.1 Ultrasound Ultrasound features of accreta may be present as early as the first trimester. In women with prior caesarean section, ultrasound examination in the early first trimester is recommended to look for features of Caesarean Scar Pregnancy (CSP), a precursor of PAS [27]. Ultrasound signs of PAS should be looked for at the early second trimester scan (11–14 weeks) and during the mid-trimester morphology scan as a routine [28]. The most common ultrasound feature in first trimester is low implantation of the gestational sac (82.4%), followed by a reduced myometrial thickness (66.8%) and placental lacunae (46.0%) [29].

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Because PAS is a progressive condition, serial follow-up scans, starting from 28 weeks of gestation should be done in order to accurately predict the degree and extent of invasion, as an aid to prognosticate and plan the appropriate surgical treatment [30]. The overall performance of ultrasound with the combination of grey-scale and colour Doppler imaging has a sensitivity of 90, and has specificity of 96.94% and diagnostic odds ratio of 98.59 as reported in a meta-analysis [31]. Technique  Diagnosis of PAS with transabdominal scan can be improved by selecting a higher frequency (5–9  MHz) transducer, preferably linear, and carefully ‘walking’ the uterine scar from one end to the other, keeping the transducer perpendicular to the uterine wall [32]. Ultrasound must be done with a full bladder (approximately 200–300 mL). The bladder outline is vital to identify the lower uterine segment, which is the presumed location of the previous caesarean delivery scar [32]. Grey-scale abnormalities that are associated with placenta accreta spectrum include multiple vascular lacunae within the placenta, loss of the normal hypoechoic zone between the placenta and myometrium, decreased retroplacental myometrial thickness (less than 1 mm), abnormalities of the uterine serosa–bladder interface, and extension of placenta into myometrium, serosa or bladder [33, 34]. Excessive probe pressure during scanning can lead to the apparent loss of the retroplacental clear zone. Therefore, this should be avoided. The loss of the retroplacental clear zone should be assessed with light probe pressure by abdominal sonography [13]. On Colour Doppler Imaging (CDI), turbulent lacunar blood flow is the most common finding. Other Doppler findings include increased subplacental vascularity, gaps in myometrial blood flow and vessels bridging the placenta to the uterine margin [33, 34]. To standardize the definitions for various ultrasound findings, group of European experts published a standardized description of ultrasonography features of placenta accreta spectrum (Table 2; Figs. 1, 2, and 3) [35]. Among the various sonographic signs of PAS, uterovesical hypervascularity on CDI has the best sensitivity (86.2%) [36]. Abnormality of the uterus bladder interface has the highest specificity (97.5–99.8%), though a low sensitivity (49.6%) [31, 36]. Despite a high accuracy for prenatal ultrasound diagnosis of PAS, a significant proportion of PAS remains undiagnosed before surgery. The reported diagnostic performance of ultrasound in detecting PAS varies and depends mainly on operator experience among other factors [37]. Hence, the absence of ultrasound findings does not preclude a diagnosis of placenta accreta spectrum and clinical risk factors remain equally important as predictors of placenta accreta spectrum.

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Table 2  Ultrasound findings in placenta accreta spectrum (PAS) disorders [35] 2D grey-scale Loss of the ‘clear zone’ Abnormal placental lacunae Bladder wall interruption Myometrial thinning Placental bulge

Loss or irregularity of the hypoechoic plane in the myometrium beneath the placental bed (the ‘clear zone’) Lacunae may be large and irregular (Finberg grade 3) containing turbulent flow are seen in placenta (Fig. 1) Loss or interruption of the bright bladder wall (the hyperechoic band or ‘line’ between the uterine serosa and the bladder lumen) Myometrium beneath the placenta to 30), diabetes, and multiparity are all factors to consider. 5. Post-term pregnancy. 6. Previous history of large for date foetus. 7. Short stature. 8. Anomalies of the pelvis.

4.2 Intrapartum 1. The protracted active phase of the first stage of labour. 2. The precipitate second stage of labour (2  h for nulliparous women, or >1  h for multiparous). 5. Short umbilical cord. 6. Conjoint twins. 7. Uterine constriction ring. 8. Induction of labour for impending macrosomia.

5 Diagnosis • The key to a better outcome is early detection of shoulder dystocia. • The time between the delivery of the foetal head and the delivery of the body is more than 60 s [3–5]. • The delivery of the shoulders has been unaffected by gentle downward traction. • The delivery of the face and chin is difficult. • External rotation fails, and the head remains pressed against the perineum (turtle-­ neck sign-head retracts into the perineum). • Failure of restitution of the foetal head and descend of shoulders. Shoulder dystocia can be diagnosed with routine axial traction, but any other traction should be avoided. Routine traction is defined as ‘the traction required for the delivery of the shoulders in a normal vaginal delivery when there is no shoulder dystocia.’ Axial traction refers to the traction that is parallel to the foetal spine, with no lateral deviation. There is no evidence that doing the McRoberts’ manoeuvre prior to foetal head delivery prevents shoulder dystocia. As a result, prophylactic McRoberts’ procedure prior to foetal head delivery is not indicated to avoid shoulder dystocia. Prevention of shoulder dystocia: Good blood sugar control. Elective induction of labour in high-risk women has not resulted in a decrease in the rate of SD. Where risk is suspected, delivery on all fours, in McRoberts, or in an upright position is planned. To avoid shoulder dystocia elective C/S can be done in high-risk cases with previous history of shoulder dystocia. All birth attendants should be familiar with the methods for diagnosing shoulder dystocia and the treatments needed to make delivery easier.

5.1 Preparation • Instruct the patient to stop pushing once shoulder dystocia is initially recognised. • Make a call for help. ‘This is shoulder dystocia,’ for example, should be mentioned clearly as it is an obstetric emergency.

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• Take note of what time the head was delivered. Our aim is to reduce head to body delivery time. The obstetrician has up to 5  min to deliver infant before an increased risk of developing asphyxia. • Take a collaborative approach. • Notify the anaesthetic and paediatrics teams, as well as the operating room. • Recruit a capable assistant to assist you with the delivery. • Do not pull baby’s head. In a study where forceful downward neck traction was given in four cases, three had brachial plexus injury and one landed in clavicular fracture. • If clinician feels that he is giving greater than normal force to deliver the shoulder, they should start manoeuvres. • If a tight nuchal cord is present should be released over the foetal head and left intact as umbilical blood flow helps in neonatal resuscitation and transition. There is no benefit of clamping and cutting to release the impacted shoulder. If cutting the cord is required to extract the foetus, it should be done after the shoulder dystocia has been resolved. • Do not ask the mother to push, since this may aggravate the shoulder impaction. • No fundal pressure. It is linked to neonatal complications and can cause uterine rupture. • Make sure her bladder is empty as it will facilitate suprapubic pressure and will relieve the space-occupying effect.

5.2 Assessment • If necessary, extend the episiotomy as it will facilitate delivery of the posterior shoulder and other manoeuvres. Analgesia should be given. • Manually examine the area behind the baby’s head to see if the baby’s posterior shoulder is in or out of the sacral hollow. • If the posterior shoulder is not in the hollow of the sacrum, bilateral shoulder dystocia (both shoulders above the pelvic inlet) is confirmed, and the best thing to do now is to restore the baby’s head within the vagina, keep the foetal head in place, and deliver the infant via caesarean section. • If the posterior shoulder is in the hollow of the sacrum (unilateral shoulder dystocia) and vaginal delivery is possible, then the following steps are to be followed.

6 First-Line Manoeuvre: McRoberts Manoeuvre MR (Hyperflexion and Slight Abduction of Thighs) (Fig. 1) The McRoberts manoeuvre is an easy, quick and successful intervention that should be used initially. It increases the relative anterior-posterior diameter of the pelvis, straightens the lumbosacral angle and rotates the maternal pelvis towards the mother’s head. It causes cephalic rotation of pubic symphysis and flattening of the sacrum. The McRoberts manoeuvre is a successful intervention with reported

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Fig. 1 McRoberts manoeuvre, done by 2 assistants, each one grasps one thigh and flexes it over mothers abdomen

success rates of up to 90% [6]. It has a low complication rate and is one of the least invasive procedures, so it should be used first. Pillows should be removed from under the woman’s back and she should be laid flat. Ask the patient to stop pushing. Abduct the mother’s legs and flex them firmly on her abdomen with one assistant on each side.

6.1 Suprapubic Pressure To aid shoulder delivery, ask the assistant to apply firm suprapubic pressure with the palm or fist aimed inferiorly and laterally to tilt the pelvis, positioning the pubic symphysis and sacrum more horizontally. Suprapubic pressure should preferably be delivered by an assistant from the side of the foetal back, right above the maternal symphysis pubis, in a downward and lateral direction. By pressing the posterior part of the anterior shoulder towards the foetal chest, the foetal bisacromial diameter is reduced and attempts to flex the anterior shoulder towards the chest. Lateral application from either side of mother’s abdomen has also been found successful. Suprapubic pressure adducts the shoulders or brings them into an oblique plane (oblique diameter is the widest diameter of the maternal pelvis). Continuous pressure and ‘rocking’ movement have no significant difference in efficacy. When assessing whether the manoeuvre was successful, only routine traction should be applied to the foetal head.

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An episiotomy will not remove the bone obstruction caused by shoulder dystocia, but it may be necessary to provide the healthcare provider additional room to do internal vaginal manipulations. If suprapubic pressure and regular traction do not release the anterior shoulder, another procedure should be attempted. There is no harm in employing MR manoeuvre prophylactically in women at high risk of shoulder dystocia nor any advantage of performing it before diagnosing SD. Hazards-Excessive force or prolonged placement of the patient’s legs in MR has led to cutaneous neuropathy symphyseal separation, sacroiliac joint dislocation, and transient lateral femoral neuropathy, in case reports.

7 Extraction of the Posterior Arm It is best performed under adequate anaesthesia. By inserting a hand into the posterior vagina if the foetal abdomen faces the maternal right, the obstetrician’s left hand is used; if the foetal abdomen faces the maternal left, the right hand is used and carefully sweeping the posterior arm of the foetus across the chest. The posterior arm should be identified and followed to the elbow. If the elbow is flexed, the operator can grasp the forearm and hand and pull out the arm. If extended apply pressure on the antecubital fossa to flex the forearm and elbow. The arm is swept out over the foetal chest, keeping the elbow flexed, followed by delivery of the arm by holding the hand of the foetus. During this time the arm is extended. The shoulder girdle is then rotated into one of the oblique diameters of the pelvis. To avoid humerus fracture which has been reported in 0–20% of cases apply pressure on antecubital fossa rather than grasping and pulling directly on the foetal arm. If we fail to reach the elbow or forearm because the posterior arm is above the pelvic brim, we deliver the posterior shoulder via the axilla (before delivering the arm), which leads to the resolution of dystocia. If the anterior shoulder cannot be delivered, the baby can be rotated and the procedure repeated for the anterior (now posterior) arm. Alternatively insert hand into the posterior pelvis, slide the first finger under the axilla and the thumb over the top of the shoulder so that the fingers encircle the shoulder and the tips of the thumb and first finger touch. The second finger is placed alongside the foetal humerus to hold the arm against the body. Now apply traction through the axilla until the posterior shoulder appears over the perineum and the anterior shoulder pivots around the symphysis leading to delivery of the posterior shoulder followed by the anterior shoulder. This was successful in more than 95 percentage cases as a first manoeuvre in a series of 119 cases.

7.1 Internal Rotational Manoeuvre Woods and Rubin were the first to describe internal rotational motions. By pressing on the anterior or posterior portion of the posterior shoulder, we can simply rotate

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the foetal shoulders. By adducting the shoulders, pressure on the posterior portion of the posterior shoulder has the additional benefit of reducing shoulder diameter. Shoulder dystocia should be corrected by rotating the shoulders into a larger oblique diameter. If applying pressure to the posterior shoulder fails, try applying pressure to the posterior side of the anterior shoulder in order to adduct and rotate the shoulders into the oblique diameter. With the women in dorsal or all four postures, rotational motions to rotate the foetal shoulders to the oblique diameter of the maternal pelvis can be performed. Woods Corkscrew Manoeuvre: This manoeuvre is performed by progressively rotating the posterior shoulder 180° in a corkscrew fashion to the anterior position and then the anterior shoulder back to the posterior position, the impacted anterior shoulder could be released which means it brings foetal bisacromial diameter into the oblique diameter of the pelvis. If the foetus is facing the maternal right side, attempt rotation in a counterclockwise direction. If the foetal spine is on the maternal left, the left hand is used to push on the clavicle of the posterior arm. If counterclockwise rotation is unsuccessful, try clockwise rotation. The Woods and Rubin manoeuvres can be combined so that one shoulder is being pushed from the front and the other shoulder is pushed from the back in the same clockwise or counterclockwise direction.

7.1.1 Manoeuvre of Rubin Rubin suggested two manoeuvres. By applying pressure to the maternal abdomen, the foetal shoulders are first rocked from side to side. If it fails, the pelvic hand reaches the easily accessible foetal shoulder, which is subsequently moved toward the chest’s anterior surface, push the foetus slightly upwards to facilitate the rotation, if the anterior shoulder is tightly under the symphysis pubis. This usually results in the abduction of both shoulders, resulting in a reduced bisacromial diameter and anterior shoulder displacement from behind the pubic symphysis. If above manoeuvre fails even after repeating them all four manoeuvre may be done.

7.2 All Four or Gaskin Manoeuvre The all-four position is probably more acceptable for a slim mobile woman without an epidural anaesthetic and with a single midwifery attendant. Internal movements are more appropriate for a less mobile woman with an epidural anaesthetic in place. Because the sacral hollow is the most spacious area of the pelvis, the vaginal entry should be achieved posteriorly, into the sacral hollow and also gravity is utilised. To conduct internal rotation or delivery of the posterior arm, the entire hand should be entered posteriorly. To make vaginal access simpler, the labouring mother should be helped onto her hands and knees (an all four position), or the end of the bed should be removed, and

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downward pressure should be provided to the foetal head to deliver the posterior shoulder. In 80% of cases, the baby will give birth naturally without the need for a second procedure [7]. It is equivalent to a sprinter position. Rotation of the shoulder to the oblique diameter of the pelvis is required in 20% of instances [7].

8 Posterior Axilla Sling Traction (PAST) It is used when other methods fail 12 or 14 French soft suction catheter or urinary catheter is folded into a loop over the index finger and fed through the posterior axilla until the loop can be retrieved with the operator’s other index finger. By unfolding the loop a sling is created around the posterior shoulder, the two ends of the sling are clamped, and the shoulder is delivered by applying traction to the sling. The sling can also rotate the shoulders 180 degrees by applying counter pressure on the back of the anterior shoulder. In a series of 19 cases, four neonates had transient Erb’s palsy and one had permanent Erb’s palsy of the anterior arm, three had posterior arm humerus fractures and five of the 19 newborns were stillborn. Third-Line Manoeuvres  To avoid possible maternal morbidity and mortality, third-line manoeuvres should be carefully considered, especially by inexperienced practitioners.

9 Zavanelli Manoeuvre-Cephalic Restitution Abdominal Rescue Caesarean delivery after cephalic replacement into the pelvis. Uterine relaxant terbutaline subcutaneously should be given. If the foetal head has rotated from either position, the initial step of the procedure is to return it to the occiput anterior or posterior position. After flexing the head and slowly pushing it back into the vagina, caesarean delivery is done. Many case reports have reported its success. The application of various techniques in a step-by-step manner to resolve shoulder dystocia should not take more than 5  min. In some dreadful circumstances, when the infant cannot be born from above or below, a symphysiotomy is required to increase the pelvic diameter and it allows birth successfully. The urethra is displaced laterally using fingers placed against the posterior aspect of the symphysis. An incision is made through the cartilaginous portion of the symphysis to allow separation of the pubic bones and this is permanent. Long-term pelvic pain and instability can remain. Urinary tract injury of the mother like lacerations of the bladder, urethra, and/or vagina; urinary incontinence; vesicovaginal fistula is a real danger. But it is life-saving.

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10 Deliberate Fracture of Clavicle Thumb is pressed against the pubic ramus to free the impacted anterior shoulder. Fracture heals rapidly and is not that serious compared to brachial plexus injury, asphyxia or death. Cleidotomy is a procedure that involves cutting the clavicle using scissors or other sharp instruments to deliver a dead foetus preferably. Prediction  Clinicians should be aware of potential risk factors in labouring women and be on the alert for shoulder dystocia. Risk factors, both individually and in combination, have a low positive predictive value. Only 16% of shoulder dystocia cases that resulted in neonatal morbidity were predicted by known risk factors. Although there is a link between foetal size and shoulder dystocia, it is not a strong predictor, partly because foetal size is difficult to precisely calculate, and partly because the large majority of newborns with a birth weight of >4500 gm do not suffer shoulder dystocia.

11 Complications Shoulder dystocia is an obstetric emergency which is unpredictable and complicates approximately 0.5-1% of vaginal births [8]. Maternal—Postpartum haemorrhage from uterine atony (1 in 10 cases according to one study) and serious perineal tears, third and fourth-degree perineal tears (4%), and uterine rupture. Foetal—SD poses more risk to the foetus compared to mother. Cord compression, compression of foetal neck vessels causing cerebral venous obstruction, excessive vagal stimulation and bradycardia may lead to hypoxia leading to hypoxic ischaemic encephalopathy. Foetal acidosis needs cardiac resuscitation, Clavicle fracture, Erb’s palsy Brachial nerve palsy—Shoulder dystocia is a major cause of brachial plexus injury neglected situations result in foetal death.

12 Things to Do After Shoulder Dystocia Occurs 1. Call for a help-senior obstetrician, anaesthesiologist, and paediatrician. 2. Drain bladder, if full. 3. Episiotomy for getting space posteriorly. 4. Gentle traction. 5. One assistant for suprapubic pressure.

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6. Mac Roberts manoeuvre. Most cases of SD will be managed by now. 7. Extraction of posterior arm. 8. Woods Cork manoeuvre. 9. Rubins method. 10. Consultation in neonatology and paediatric neurology. 11. Each manoeuvre can be repeated two to three times before moving on to the next manoeuvre. 12. Keep comprehensive delivery notes, including any manoeuvres that were used including notes by all staff, nurses, paediatricians and anaesthetist. Document the time when paediatrician was called. 13. Explain the cause of dystocia to the parents. 14. Be truthful, but prevent disparities in doctor’s, midwife’s, and nurse’s notes. 15. Check for and treat injuries to the reproductive tract if dystocia occurs. Simulation-based teaching is really effective for learning.

References 1. Ouzounian JG, Gherman RB. Shoulder dystocia: are historic risk factors reliable predictors? Am J Obstet Gynecol. 2005;192:1933–5. Discussion 1935–8. 2. Usta IM, Hayek S, Yahya F, Abu-Musa A, Nassar AH.  Shoulder dystocia: what is the risk of recurrence? Acta Obstet Gynecol Scand. 2008;87(10):992–7. https://doi. org/10.1080/00016340802415614. PMID: 18927947. 3. https://www.rcog.org.uk/globalassets/documents/guidelines/gtg_42.pdf. 4. Spong CY, Beall M, Rodrigues D, Ross MG. An objective definition of shoulder dystocia: prolonged head-to-body delivery intervals and/or the use of ancillary obstetric maneuvers. Obstet Gynecol. 1995;86:433–6. 5. Beall MH, Spong C, McKay J, Ross MG. Objective definition of shoulder dystocia: a prospective evaluation. Am J Obstet Gynecol. 1998;179:934–7. 6. Resnick R. Management of shoulder dystocia girdle. Clin Obstet Gynecol. 1980;23:559–64. 7. Bruner JP, Drummond SB, Meenan AL, Gaskin IM. All fours maneuver for reducing shoulder dystocia during labour. J Reprod Med. 1998;43:439–43. 8. Bothou A, Apostolidi D, Tsikouras P, Iatrakis G, Sarella A, Iatrakis D, et al. Overview of techniques to manage shoulder dystocia during vaginal birth. Eur J Midw. 2021;5:1–6. https://doi. org/10.18332/ejm/142097.

Obstructed Labour Vijayata Sangwan and Pinkey Lakra

Obstructed labour is defined as the failure of the foetus to descend through the birth canal in spite of good uterine contractions. It is an important indicator of a nation’s maternal and child health care facilities as it is a preventable obstetric complication. The incidence of obstructed labour has become negligible in developed countries and institutionalisation of delivery, but it is still high in underprivileged parts of the world. A systematic review and meta-analysis published in 2021 stated that the pooled incidence of obstructed labour is up to 12.93% in Ethiopia, in other countries it is 1.9% (India), 2.1% (Pakistan), 4.7% (Nigeria), and 10.5% Uganda. The main cause of obstructed labour is cephalopelvic disproportion followed by malpresentations. Early recognition of abnormal labour and immediate intervention can prevent obstructed labour. The causes of obstructed labour are as follows: Passenger Foetal malpresentations (face presentation, brow presentation) and malpositions (persistent occipitoposterior, mento posterior position) Oblique or transverse lie Macrosomia, foetal hydrocephalus, foetal ascites, foetal tumours Conjoined twins, locked twins

Passage Bony obstruction (contracted pelvis) Soft tissue obstruction (fibroids impacted in pelvis, ovarian mass) Cephalopelvic disproportion Constriction ring around foetal neck Cervical dystocia, vaginal septum

Clinical Presentation  A patient of obstructed labour usually presents in the exhausted state with a history of pain in the abdomen and leaking per vaginum for more than 24 h. Patient has a dehydrated look with dried-up lips and is agitated with pain. On examination, she may have acidotic breath and tachycardia.

V. Sangwan (*) · P. Lakra BPS Government Medical College for Women, Khanpur Kalan, Sonipat, Haryana, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_24

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a

b

Fig. 1  Bandl’s ring. (a) Line diagram of abdomen in normal labor women. (b) Line diagram of abdomen in obstructed labor showing Bandal’s ring

Figure 1 shows the finding on abdominal examination where the uterus may be hard and tender in the upper part with a Bandl’s ring felt as a groove across the abdomen ascending upwards and the round ligaments feel tense cord-like structures bilaterally. Lower uterine segment will be distended and a full bladder may be there. Sometimes the foetal head may also be palpable per abdominally, foetal heart sounds are usually absent and foetal parts are difficult to palpate. On local examination shows edema and erythema of Vulva, foul-smelling vaginal discharge and dried up hot vagina. Fetal head may be felt impacted in the pelvis with high-grade of moulding and Caput formation with absent membranes. In cases of malpresentation sometimes a neglected shoulder, a prolapsed arm or hand may be there in the vagina.

1 Complications of Obstructed Labour Uterine Rupture  in multiparous females, obstructed labour may result in a rupture of the uterus mainly affecting the lateral wall resulting in hysterectomy. In primigravida since the uterus is strong and young enough the uterus ultimately tires and goes into inertia. Septicaemia  It is seen in 38.59% cases. Operative Interventions  The mode of delivery is by caesarean section resulting in complications like postpartum haemorrhage, septicaemia, peritonitis, blood transfusion, wound infection, burst abdomen, prolonged hospital stay and even death. Even

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the patients delivered after vaginal foetal destructive surgery may also land up in uterine rupture (2.6–9.1%), postpartum haemorrhage (4.5%) and cervical & vaginal lacerations. Fistula  Women who remain in obstructed labour for prolonged time are prone to develop vesicovaginal fistula by seventh to eighth postoperative day because of necrosis and sloughing of bladder mucosa compressed between foetal head and pubic bone. Even during caesarean section or vaginal destructive procedures also these patients are predisposed to bladder and gut injury. Maternal Mortality and Morbidity  A study in Ethiopia reported maternal mortality in 17.3% of patients. Even the morbidity secondary to various complications and prolonged intensive care unit (icu) stay is also significantly high [1]. Neonatal Complications  The reported still birth rate is up to 38.59% and other complications include birth asphyxia, seizures, neonatal jaundice and neonatal sepsis. Long- Term Complications  Long-term complications of obstructed labor are infertility and repeat cesarean section in subsequent pregnancies. Obstructed labour affects a female’s life physically, mentally as well as socially [2].

2 Management of Obstructed Labour The stepwise management of a patient with obstructed labour includes the following: Treatment of Shock  The management starts with reassurance to the patient, put wide bore cannula and rush normal saline or ringer lactate. First 1 L is to be rushed and later 1 L every 30 min until her pulse rate is below 90 per min. Clean the perineal area with povidone iodine solution and catheterise the bladder with an appropriate size Foleys catheter, in severe cases of obstruction due to the deeply impacted presenting part it is difficult to catheterise the bladder. In such circumstances, presenting part may be pushed upwards before putting Foleys catheter. Considering high probability of postpartum haemorrhage blood and blood products should be arranged and to avoid puerperal sepsis high-grade antibiotics are being started. In today’s obstetric scenario where caesarean is considered as a safe mode of delivery and limited exposure as well as experience of destructive surgeries irrespective of foetal status. However, in experienced hands various destructive procedures like craniotomy, decapitation, evisceration, symphysiotomy may be attempted. In patients with foetal hydrocephalus or foetal ascites per vaginum craniocentesis and abdominal paracentesis would save the patient from caesarean section.

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The caesarean section must be done in presence of senior obstetrician and the incision on the uterus should be given just below the UV fold of the peritoneum. The lower segment in these patients is distended so a low incision may result in opening of vagina. This may result in a difficult approximation of upper and lower flaps. Post-surgery such patients should be taken either to the intensive care unit or high dependency unit and special attention should be given to maintain general hygiene by betadine vaginal douching and bladder care by keeping Foleys Catheter for 7–10 days to avoid fistula formation. Prevention of Obstructed Labour  For any event, we need preparation and labour process is a supreme event in woman’s life [3]. So prepare women for this event of their life by empowering them with knowledge of process of labour and developing a health care-seeking attitude. Partograph or labour care guide must be followed strictly for early detection of prolonged labour and abnormal labour.

References 1. Ayenew AA.  Incidence, causes and maternofetal outcomes of obstructed labor in Ethiopia: systematic review and meta-analysis. Reprod Health. 2021;18:61. 2. Mondal S, Chaudhari A, Kamilya G, Santra D. Fetomaternal outcome in obstructed labor in a peripheral tertiary care hospital. Med JDY Patil Univ. 2013;6:146–50. 3. WHO recommendations on labor care guide. 2018.

Episiotomy: Recent Recommendations Sadaqat Jabeen and Munjal Pandya

1 Introduction Episiotomy is defined as a deliberate/planned incision given in the perineal body and vagina to enlarge the introitus which will help to facilitate the delivery of baby [1]. First ever description was in the year 1742, with its entry into the USA in the mid-nineteenth century [2]. Dr. Joseph DeLee first advocated mediolateral episiotomy in all nulliparous women [3]. In the past, it was the most frequently performed procedure, the reported incidence in 1979 was 62% in all deliveries in the United States, and in nulliparous it rose to 80%. Since that time the routine use of episiotomy has been increasingly questioned. In 2004 the rate of episiotomy with all vaginal births was 24.5% [1]. Considering the complications and higher morbidity rate associated with it, a restricted or selective instead of routine approach has been adapted in many institutions of the world. JAMA, ACOG, NICE and RCOG recommended against routine episiotomy and when indicated, preferred mediolateral episiotomy [4–7]. World Health Organization (WHO) does not recommend the routine episiotomy, 10% episiotomy rate is recommended by it [8]. The restricted role of episiotomy is cited in difficult deliveries, non-reassuring foetal heart sounds and to avoid maternal lacerations [5, 9, 10]. In the study by Mengqin Zhang of 3721 women in China risk factors significantly associated with episiotomy were the primiparity and prolonged second stage of labour. Risk factors specific to primiparas were increasing maternal age (per year) (OR = 1.04), increasing biparietal diameter (per centimetre) (OR = 1.40), the

S. Jabeen (*) Obstetrics/Gynea Department, PGMI/Lady Reading Hospital, Peshawar, Pakistan M. Pandya AMC MET Medical College, Ahmedabad, Gujarat, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_25

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first stage of labour beyond 10-hour (OR = 1.36) and birth weight (per 100 g) (OR = 1.06). There was an adjusted risk increase of 6.1% among primiparas for every 100 additional grams of birth weight.

2 Episiotomy: Why It Should Be Given? Episiotomy is invented to facilitate the completion of the second stage of labour, thus minimizing morbidity and mortality of neonate as well as mother. Deliberate incision does have its own advantages in form of prevention of haphazard third and fourth degree perineal tears, ease of suturing incision and reduced post-procedural pain. Fear of anal sphincter trauma in short perineal body or long rigid, firm, inelastic and oedematous perineum is an important indication of episiotomy. Episiotomy has its own long-term benefits in form of prevention of pelvic organ prolapse, sexual dysfunction and urinary and faecal incontinence. Neonates are saved from the pressurized and difficult passage, thus avoiding cranial trauma, asphyxia, cerebral haemorrhage and shoulder dystocia.

3 Types of Episiotomy The followings are four types of episiotomy. 1. 2. 3. 4.

Midline Mediolateral J shaped Lateral

3.1 Midline Episiotomy It is commonly practiced in the United States, in which the incision is given from the vagina straight down towards the anus (it should not involve the anal sphincter) passing through the superficial transverse perineal muscles and perineal membrane.

3.2 Mediolateral Episiotomy It is commonly practiced in the UK and many parts of the world, WHO also recommends mediolateral episiotomy. In this episiotomy, the incision is given from the midpoint of the fourchette directed at 45° from the midline and then extended towards the midway between the ischial tuberosity and anus. Sixty-degree angle is proposed as part of a definition of mediolateral episiotomy. In this episiotomy posterior vaginal wall, superficial and deep transverse perineal muscles,

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bulbospongiosus muscle, part of levator ani muscles, the fascia covering these muscles, pudendal nerve and vessels, subcutaneous tissue and skin are cut. Though the mediolateral episiotomy is associated with more disadvantages, but primary advantage of less association with anal sphincter damage outweighs the other risks, hence commonly used. As per ACOG recent recommendation, mediolateral episiotomy may be preferred to midline episiotomy when indicated [5, 6].

3.3 J-Shaped This incision begins in the centre of the fourchette and is extended at least 1.5 cm in the midline, and then extended towards 5 o’clock (At first midline, then ‘J’ is directed towards the ischial tuberosity) to avoid extension into anal sphincters. The mentioned type is not used much.

3.4 Lateral Episiotomy This type of episiotomy is totally obsolete. It is given laterally towards the ischial tuberosity. The choice of episiotomy depends upon the personal judgment and experience of the obstetrician also the adapted practice of the institutions.

4 Contraindications Episiotomy must not be performed without the informed consent of the patient [11]. It should not be performed whenever vaginal delivery is not possible. Inflammatory bowel disease and severe perineal malformations are relative contraindications.

5 Structures to Cut by Incision Incision is given in the Vaginal mucosa Perineal body Perineal skin The perineal body is the point of junction of the superficial and deep transverse perineal muscles, bulbospongiosus muscles, perineal membrane, external anal sphincter, posterior vaginal muscularis and fibres from the puborectalis and pubococcygeus muscles.

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6 Timing and Technique of Episiotomy To minimize the complications associated with episiotomy, proper time and technique is very important. The best time to perform an episiotomy is when the presenting part of the foetus starts crowning and remains visible during a contraction. To prevent the excessive loss of blood it is very necessary to give episiotomy very close to the delivery of baby after crowning. Episiotomy done after crowning is associated with less additional vaginal trauma less estimated blood loss and lower incidence of painful defecation.

7 Prerequisites Verbal consent of the patient. Proper indication. Proper light source. Proper position of the patient mostly lithotomy position.

8 Instruments 1. Episiotomy scissors. These special scissors are used to give incisions for episiotomy. These are made angled with smooth blunt tips and are available in different lengths (Fig. 1). 2. Needle holder. 3. Suture materials. Fig. 1  Episiotomy scissor

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Polygalactin 910 (coated Vicryl, Vicryl RAPIDE, 2-0) is used commonly and the advantage is less postoperative pain and wound dehiscence compared to chromic catgut. If Vicryl is used there might be a need to remove the residual sutures because of pain and dyspareunia, but this is not the problem with Vicryl rapid. Polyglycolic acid (Dexon, Safil) Traditional sutures (catgut, chromic catgut) 4. Surgical drape. 5. Local anaesthetic (1% lidocaine solution). 6. Haemostatic forceps/tissue forceps. 7. Syringes 10 mL. 8. Gauze swabs. 9. Sterile gloves.

9 Technique Perineal body and posterior vaginal wall are cleaned with antiseptic lotion infiltrated with 10 mL of 1% lidocaine for local anaesthesia. Choice of type of episiotomy depends upon the preference of obstetrician and routine of the institution. Mediolateral episiotomy is commonly performed in most of the areas of the world. Whatever the choice, episiotomy is given at the time of crowning (when 3–4 cm of head is visible) or for forceps delivery after the application of blades. Two fingers are placed between the vagina and presenting part. Incision is given with episiotomy scissors at the height of uterine contraction as described above. It should be adequate to serve the purpose. Active heavy bleeding can be controlled with the application of artery forceps. After delivery of the baby and the placenta, cervix, vagina and perineum are inspected carefully for any lacerations or tears or extension of episiotomy. Stitching before the separation of the placenta is not advisable especially in cases where manual removal of the placenta is required.

10 Suturing of Episiotomy Suturing of episiotomy requires adequate light. If any laceration or tear is detected it should be stitched first. Aseptic technique and adequate analgesia should be ensured. The episiotomy wound should be closed in layers. Closure of the vaginal wall is the first step which should start 1 cm above the apex of the incision with Vicryl rapid (or any absorbable suture of choice). Suture material can be chromic catgut, but rapid absorption polyglycolic acid sutures are having the benefit of a minimally reactive nature. Care should be taken to identify retracted blood vessels and take them into the stitch to avoid haematoma formation. All dead spaces are obliterated carefully. Closure of the vaginal wall should be completed till the hymeneal ring. It is to

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avoid taking stitch at the mucocutaneous junction of the fourchette to avoid dyspareunia. The superficial transverse perineal muscles and bulbospongiosus are reapproximated to help reconstruct the perineal body. Continuous or interrupted sutures are given depending upon the choice of the obstetrician. In many randomized controlled trials and systematic reviews and meta-analysis, continuous suturing techniques have been compared with the interrupted method and it has been found that there was less short-term postpartum pain, less need for analgesia and suture removal with continuous suturing as compared to interrupted technique. Furthermore, there is also some evidence that the continuous techniques used less suture material as compared with the interrupted methods (one packet compared to two or three packets, respectively) [12, 13]. The continuous stitch is carried upward as a subcuticular stitch. The perineal skin is stitched in a continuous subcutical layer. After completion of the repair, the vagina should be examined for any gap, stitch extending into the rectum, any residual bleeding or any sponge left in it. Vagina should be cleaned. Rectal examination must to ensure sphincter integrity or any stitch extending into it.

11 Care of Episiotomy Postnatal daily care of the episiotomy is very important to prevent complications. The wound should be cleaned and kept dry. For relief of acute pain, several modalities have been used. Use of cooling treatments like cool gel, ice packs or iced baths has been advised and found to be beneficial to some extent, due to its cheap cost and easy availability and can be considered for the satisfaction of the patients [14]. Sitz baths have also been recommended. Simple analgesics like oral paracetamol, ibuprofen or diclofenac suppositories have been proven to be effective in relieving pain [15].

12 Complications As with any surgical procedure, episiotomy is also associated with immediate and remote complications. As pregnancy increases the blood supply for the growing embryo (then foetus), the vascularity might lead to more bleeding due to episiotomy, ignoring which, may lead to haematoma formation. Pain may be an indication of vulvar or paravaginal haematoma. Immediate complications include an extension of the incision to involve the rectum, primary haemorrhage, vulval haematoma, infection, disruption of wound, rectal fistula and necrotizing fasciitis (rare). The risk of complications further increases with operative vaginal delivery.

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Third and fourth-degree perineal tears are noticed in 1% of cases without any episiotomy, 9% in mediolateral episiotomy and 20% in cases of midline episiotomy [16]. Infection, faecal incontinence and fistula formation are usual outcomes in case of missed extension/vaginal lacerations. Unnoticed haematoma might lead to its extension towards the upper vagina and even up to the broad ligament, leading to hypovolemic shock in extreme cases. Extension to involve the rectum is more common with midline episiotomy [4, 5]. As muscular involvement will be there with mediolateral episiotomy, bleeding will be more as compared to midline episiotomy. Infection is common after episiotomy, as the site is heavily loaded with a septic environment, mainly due to commensal organisms with reduced local defence due to pregnancy as well as frequent proximity and passage of stool during labour. Such infection may present as fever, local tenderness at the site of episiotomy and foul-­ smelling purulent discharge. Antibiotics depending upon the severity of the infection need to be given, along with necessary local site intervention. Episiotomy wound dehiscence may occur, which may or may not have associated infection. Local wound debridement, antibiotics and if required, suturing of the wound needs to be done [17]. Remote complications include dyspareunia, persistent discharge due to granulation tissue formation and badly healed scar tissue. Recovery from episiotomy is delayed by urinary retention.

13 Routine or Selected Episiotomy Routine episiotomy is a planned procedure done irrespective of indication in all labouring women undergoing for vaginal delivery, specially in primigravda to reduce the risk of tears and lacerations. Restrictive approach is done in a subgroup of women when there is real need. Considering the complications associated with episiotomy the routine or liberal use of episiotomy has been discouraged. Current evidence suggests that adopting the policy of selective or restricted approach can reduce the rate of episiotomy [17]. World Health Organization does not recommend routine or liberal use of episiotomy and 10% episiotomy rate has been recommended by it [8]. American College of Obstetricians and Gynecologists (ACOG) guidelines state that ‘the best available data do not support the liberal or routine use of episiotomy. However, there is a role for episiotomy for maternal or fetal indications such as avoiding severe maternal lacerations or to facilitate difficult births’ [18]. It has been advised that the decision of giving an episiotomy should depend upon the judgment of the obstetrician for the need of episiotomy. FIGO (Federation of Obstetricians and Gynecologists) also support and endorsed the policy of a restricted approach [19]. In a systematic review, no benefits have been found in routine episiotomy over the restricted approach [4].

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Key Points

1. Episiotomy is a simple procedure to facilitate the vaginal delivery. 2. Timely episiotomy reduces the chance of complications. 3. Mediolateral episiotomy is commonly used. 4. Midline episiotomy is associated with anal sphincter damage. 5. Continuous suturing technique is associated with less postnatal pain. 6. Many recent evidence-based research recommends a restricted rather than routine approach.

14 What Is New? In a study by Subramaniam, N [20] in women after the repair of obstetric anal sphincter injuries, 76 women with a history of episiotomy were analysed. Episiotomy scars were interpreted on tomographic ultrasound in the transverse plane. The mean scar angle was 50.5°, in the acceptable range of 40–60°, the mean scar length was 14.2 mm, the depth was 8.4 mm, 21% scars were mediolateral while 42% were ipsilateral. In 37%, the starting point of the episiotomy was located contralateral to the direction of the episiotomy. The risk of third-degree tear is reduced to half for every 6° away from the perineal midline that an episiotomy was cut [21]. More than 70% of women with an episiotomy complain of pain on day 7 after delivery and 42% have at least 1 complaint like difficulty in sitting, urinary problem, walking or sleeping. Glutton C infiltrated 20 mL of lidocaine 10 mg/mL in one group and 20 mL of ropivacaine 7.5 mg/mL in another group, reduction in pain was greater when ropivacaine was used for post-episiotomy analgesia even at 2, 24 and 48 h after infiltration with improved maternal satisfaction in the ropivacaine group [22]. Restricted episiotomy for primiparous deliveries ranged from 8 to 53%. Restrictive episiotomy only for foetal indications resulted in a one third decrease in the episiotomy rate, and a threefold increase in the rate of intact perinea and the rate of minor perineal trauma. Women who delivered over an intact perineum or with only a first-degree tear reported the best outcomes for postpartum sexual functioning. The mean umbilical arterial pH and Apgar score did not differ between the restrictive and liberal episiotomy group suggesting that avoiding episiotomies at tears judged to be imminent does not lead to foetal hypoxia [23]. Episiotomy rates are around 40–70% of all vaginal births. There is a decrease of obstetrical anal sphincter injury (OASIS) rate if using episiotomy. The episiotomy rate decreased significantly from 2004 to 2020, 43.2% to 20% in the total population. OASIS rate of 0.34% remained significantly the same although the association between OASIS and episiotomy was significant only in nulliparous women with instrumental delivery with a decrease of OASIS rate if using episiotomy (odds ratio 0.5) [24].

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Around 150 episiotomies would be needed to prevent a single case of OASIS among primipara [25]. The practice of restrictive episiotomy offers benefits in terms of more intact perineums after delivery, fewer mild perineal lacerations in multiparous women and the lower risk of severe perineal laceration among primiparous women. A policy of restrictive episiotomy should be recommended for all women, especially for multiparous women [26].

References 1. Cloutier AM. Episiotomy. McGill Med J. 1951;20(1):36–9. Available http://www.glowm.com/ section-­view/heading/Episiotomy/item/128. 2. Ould F. A treatise on midwifery in three parts. Dublin: Nelson & Connor; 1742. 3. DeLee JB. The prophylactic forceps operation. Am J Obstet Gynecol. 1920;1:34–44. 4. Hartmann K, Viswanathan M, Palmieri R, Gartlehner G, Thorp J Jr, Lohr KN. Outcomes of routine episiotomy: a systematic review. JAMA. 2005;293(17):2141–8. 5. American College of Obstetricians-Gynecologists. ACOG practice bulletin. Episiotomy. Clinical management guidelines for obstetrician-gynecologists. Obstet Gynecol. 2006;107(4):957–62. 6. Committee on Practice Bulletins-Obstetrics. ACOG practice bulletin No. 198: Prevention and management of obstetric lacerations at vaginal delivery. Obstet Gynecol. 2018;132(3):e87–e102. 7. National Collaborating Centre for Women’s and Children’s Health. Intrapartum care: care of healthy women and their babies during childbirth. London: RCOG Press; 2007. 8. World Health Organization. WHO recommendation on episiotomy policy. WHO Reprod Heal Libr. 2018;2:1–10. 9. Chauhan SP, Gherman R, Hendrix NW, Bingham JM, Hayes E.  Shoulder dystocia: comparison of the ACOG practice bulletin with another national guideline. Am J Perinatol. 2010;27(2):129–36. 10. Paris AE, Greenberg JA, Ecker JL, McElrath TF. Is an episiotomy necessary with a shoulder dystocia? Am J Obstet Gynecol. 2011;205(3):217. 11. Varner MW.  Episiotomy: techniques and indications. Clin Obstet Gynecol. 1986;29:309. Ramin SM, Gilstrap LC.  Episiotomy and early repair of dehiscence. Clin Obstet Gynecol. 1994;37:816. 12. Kettle C, Hills RK, Ismail KMK. Continuous versus interrupted sutures for repair of episiotomy or second degree tears. Cochrane Database Syst Rev. 2007;4:CD000947. 13. Kettle C, Dowswell T, Ismail KM. Continuous and interrupted suturing techniques for repair of episiotomy or second-degree tears. Cochrane Database Syst Rev. 2012;11(11):CD000947. 14. Moore W, James DK.  A random trial of three topical analgesic agents in the treatment of episiotomy pain following instrumental vaginal delivery. J Obstet Gynaecol. 1989;10(1):35–9. 15. Schachtel BP, Thoden WR, Baybutt RI. Ibuprofen and acetaminophen in the relief of postpartum episiotomy pain. J Clin Pharmacol. 1989;29(6):550–3. 16. Owen J, Hauth JC.  Episiotomy infection and dehiscence. In: Gilstrap LC, Faro S, editors. Infections in pregnancy. New York: Alan R Liss; 1990. 17. Melo I, Katz L, Coutinho I, Amorim MM. Selective episiotomy vs. implementation of a non episiotomy protocol: a randomized clinical trial. Reprod Health. 2014;11(1):66. 18. ACOG. ACOG Practice Bulletin. Episiotomy. Clinical management guidelines for obstetrician-­ gynecologists. Number 71, April 2006. Obstet Gynecol. 2006;107(4):957–62. Available http:// intl.greenjournal.org/cgi/content/full/107/4/957.

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19. Nassar AH, Visser GH, Ayres-de-Campos D, Rane A. FIGO statement: restrictive use rather than routine use of episiotomy. Int J Gynaecol Obstet. 2019;146(1):17–9. Available https:// europepmc.org/article/med/31058312. 20. Subramaniam N, Shek KL, Dietz HP. Imaging characteristics of episiotomy scars on translabial ultrasound. J Ultrasound Med. 2022;41(9):2287–93. https://doi.org/10.1002/jum.15915. 21. Eogan M, Daly L, O’Connell P, O’Herlihy C. Does the angle of episiotomy affect the incidence of anal sphincter injury? BJOG. 2006;113:190–4. 22. Gutton C, Bellefleur J-P, Puppo S, Brunet J, Antonini F, Leone M, Bretelle F. Lidocaine versus ropivacaine for perineal infiltration post-episiotomy. Int J Gynecol Obstet. 2013;122:33–6. 23. Dannecker C, Hillemanns P, Strauss A, Hasbargen U, Hepp H, Anthuber C. Episiotomy and perineal tears presumed to be imminent: randomized controlled trial. Acta Obstet Gynecol Scand. 2004;83:364–8. 24. Morgan R, Korb D, Sibony O. Classification and evaluation of episiotomy practices from 2004 to 2020 and association with OASIS. Int J Gynecol Obstet. 2022;159(1):237–45. 25. Räisänen SH, Vehviläinen-Julkunen K, Gissler M, Heinonen S. Lateral episiotomy protects primiparous but not multiparous women from obstetric anal sphincter rupture. Acta Obstet Gynecol Scand. 2009;88(12):1365–72. 26. Sangkomkamhang U, Kongwattanakul K, Kietpeerakool C, Thinkhamrop J, Wannasiri P, Khunpradit S, Thepsuthamarat K, Jampathong N, Lumbiganon P. Restrictive versus routine episiotomy among Southeast Asian term pregnancies: a multicentre randomised controlled trial. BJOG. 2020;127:397–403.

Third and Fourth Degree Perineal Tears: Surgical Aspects Avantika Gupta and Haritha Sagili

1 Introduction The famous proverb ‘a stitch in time saves nine’ holds true for repair of third- and fourth-degree perineal tears. Knowledge of perineal anatomy including the anal sphincter complex is essential for the classification of third- and fourth-degree perineal tears (Fig. 1), which are defined as follows: • First-degree perineal tear: Involves perineal skin and subcutaneous tissue between vaginal opening and rectum but perineal muscles are intact • Second-degree perineal tear: Extends to fascia and muscles of the perineal body but the anal sphincter muscle complex is intact • Third-degree perineal tear: Involves muscles of the perineal body as well as anal sphincter muscles. It is further classified as: –– Grade 3a tear: Less than 50% of the external anal sphincter (EAS) thickness is involved –– Grade 3b tear: More than 50% of EAS thickness is involved –– Grade 3c tear: Full thickness of anal sphincter complex [EAS and IAS (Internal anal sphincter)] is involved • Fourth-degree perineal tear: Injury to the perineum involving the anal sphincter complex as well as the anorectal mucosa In case of difficulty in assigning the grade of third-degree tear, it is suggested to assign a higher degree rather than the lower degree. A. Gupta Department of Obstetrics and Gynaecology, AIIMS, Nagpur, Nagpur, India H. Sagili (*) Department of Obstetrics and Gynaecology, JIPMER, Puducherry, India e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_26

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360 Fig. 1  Classification of third- and fourth-degree perineal tears

A. Gupta and H. Sagili 3a

3b 3c

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IAS EAS

2 Timing of Repair Once a third- or fourth-degree perineal tear is recognized in the labour room, the patient should be shifted immediately for repair under anaesthesia to the operation theatre. If there is excessive bleeding, vagina can be packed using roller gauze. A waiting time period of 8–10 h for arranging expertise is acceptable if there is no bleeding or any other risk factors [1, 2].

3 Place of Repair/Surgical Competence Repair of third- and fourth-degree perineal tears should be performed or directly supervised by a trained obstetrician in the operation theatre with good lighting. Formal training in third- and fourth-degree perineal tears repair must be included in postgraduate training in obstetrics. Only under exceptional circumstances, repair may be performed in the delivery room if a sterile environment and adequate lighting can be ensured [3]. Repair of upto 3a tear is permissible in the delivery room, according to South Australian guidelines [4]. It is a safe practice to involve a colorectal surgeon in case of a large fourth-degree perineal tear.

4 Preoperative Preparation 4.1 Consent Written informed consent should be taken prior to the procedure, explaining about favourable outcome of the repair in most cases and the associated complications, which can occur after the repair.

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4.2 Antibiotics A single dose of any broad-spectrum antibiotic is recommended at the time of thirdand fourth-degree perineal tear repair to reduce the risk of post-operative wound infection and dehiscence. Most of the guidelines recommend a single dose of second generation Cephalosporin (Cefotetan or Cefoxitin) and a few advocate Cefuroxime with Metronidazole. However, it is better to prescribe antibiotics according to the hospital-based antibiotic policy [2].

4.3 Shaving Shaving is not recommended; however, clipping of hair can be done if it interferes with the repair as the former facilitates entry of organisms through minor cuts.

4.4 Anaesthesia Either general or regional anaesthesia should be used to facilitate comfort and positioning. Providing adequate analgesia will help in sphincter relaxation and will help in identifying and pulling out the retracted edges of the torn anal sphincter.

4.5 Positioning After anaesthesia, the patient is laid in a dorsal lithotomy position using stirrups for adequate exposure of the tear.

4.6 Scrub The operating field, namely, the perineum and vagina, should be cleaned with a 4% Chlorhexidine solution and a sterile drape should be applied [5].

4.7 Foley Catheter Self-retaining catheter for continuous bladder drainage should be placed prior to the repair and continued in the post-operative period for at least 12 h.

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5 Intraoperative Aspects 5.1 Instruments The operation theatre trolley should have the following instruments: Allis tissue holding forceps (4 Nos), mosquito artery forceps (4 Nos), Metzenbaum scissors, needle holder, Rigby self-retaining vaginal retractor or Sims anterior vaginal wall retractor (2 Nos), sponge holding forceps and atraumatic needles with sutures and sponges.

5.2 Identification of Severity of Damage The full extent of the tear must be again determined under anaesthesia by palpating the anal sphincter between the index finger of the dominant hand kept in the anal canal and the ipsilateral thumb in the vagina in a ‘pill-rolling’ fashion. If the tear involves only the rectal mucosa whereas anal sphincter muscles are intact, it is classified as a rectal ‘button hole tear’ and if unrecognized, it may lead to the formation of a rectovaginal fistula later.

5.3 General Principles of Repair The three general principles of repair are good anatomical approximation without the formation of dead space, adequate haemostasis and restoration of continuity. Fine sutures which cause minimal tissue reaction on a tapered needle should be used for the repair of all the layers. The figure of eight hemostatic sutures should be avoided as these can cause ischaemia of tissues [3, 6]. Each layer must be identified and repaired separately in order to restore normal anatomy and function. The repair should always be conducted from the proximal to the distal end as this ensures easy access to the upper end. Absorbable sutures should be used and knots in each layer should be buried to reduce the risk of dyspareunia and vaginal discomfort following the surgery.

5.4 Surgical Technique Once the extent of the tear is defined, the repair should begin layer-wise after identifying each layer, namely: anorectal mucosa, IAS, EAS, perineal muscles, vagina and skin as described below.

5.4.1 Repair of Anorectal Mucosa Repair of the torn anorectal mucosa should start at least 1 cm above the apex of the laceration. There are two methods to stitch the mucosal layer. The first method is to take interrupted sutures with the knots tied either in the lumen (Fig. 2a) or external to the lumen (Fig. 2b) with 3-0, 4-0 Polyglactin suture [3] on a tapered needle; a

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Fig. 2 (a) Interrupted sutures with knots within the lumen. (b) Interrupted sutures with knots outside the lumen. (c) Continuous non-locking suture

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monofilament suture such as poliglecaprone 25 can also be used. It dissolves by hydrolysis and doesn’t cause tissue reaction. The second method is a running non-locking suture (Fig. 2c) of the mucosal layer. Either of the two techniques can be used as there are no proven benefits of one method over another. Restoration of radiating anal folds marks the completion of this layer. PDS should be avoided for the mucosal layer as it takes longer to dissolve and can cause more discomfort [3].

5.4.2 Repair of IAS IAS is responsible for 70–85% of the resting anal tone [6, 7]. Hence, it should be sutured separately to restore its function. Studies have shown that patients who have persistent IAS defects on endoanal ultrasound at 6 months report anal incontinence [8, 9]. IAS is the continuation of circular rectal smooth muscle and compared to EAS, this layer is paler and much thinner with a thickness of a few millimetres. The length of EAS is approximately 1.7–2 cm and IAS extends further 1.2 cm cephalad to EAS [5]. The detailed anatomy of IAS in relation to EAS is shown in Fig. 1. If not seen as a distinct layer, the tissue between rectal serosa and EAS fascial sheath should be considered as IAS layer. It often retracts laterally and superiorly. IAS is identified as a thickened, pale pink, shiny tissue just above the anal mucosa. This should be sutured by the end-to-end method with interrupted sutures (Fig. 3a) of 2-0, 3-0 Polyglactin or 3-0 PDS on a tapered needle and should never be overlapped [1, 3, 10]. Sultan et al. who first described the approximation of IAS separately recommend continuous non-locking suture for the repair of torn IAS (Fig. 3b) [7]. There is a lack of evidence-based data to evaluate the outcomes with the use of these sutures; however, with the use of such fine sutures, complications are unlikely. Reapproximation of IAS is important for strength, integrity and for anal continence. 5.4.3 Repair of EAS Full Thickness EAS Tear (3c/4) The muscle belly of EAS can retract within the fascial sheath because of its tonic contraction and should be palpated posteriolateral to the laceration in a downward depression. Allis clamp should pull deep into the surrounding connective tissue to locate the sphincter since one or both ends retract at during the tear. Once identified, the torn ends (dark red) should be pulled out with the help of Allis forceps. There are two recommended techniques, namely, overlapping (Fig. 4a) and end-to-end approximation (Fig. 4b) using 2-0 Polyglactin or 3-0 PDS for the repair of full thickness EAS tear. Care should be taken to include the fascial sheath along with the muscle belly of EAS. Overlapping Repair

EAS needs to be dissected with Metzenbaum scissors till ischio-rectal fat appears. Then the torn ends are mobilized to midline with an overlap of about 1–1.5 cm on both ends and approximated using a double row of sutures in a double breasting fashion, sharply mobilizing the ends to achieve better anastomosis and minimize

Third and Fourth Degree Perineal Tears: Surgical Aspects

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b

Fig. 3 (a) Interrupted sutures. (b) Continuous non-locking suture

a

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Fig. 4 (a) Overlapping repair. (b) End-to-end repair

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tension. The suture ends should be trimmed and knots should be buried in perineal muscles to avoid suture migration [9]. With the overlapping technique, there is a greater surface area of contact between muscles. End-to-End Repair

When overlapping is not possible, end-to-end approximation should be carried out. End-to-End versus Overlapping Repair

According to a 2013 Cochrane review, perineal pain and dyspareunia were similar at the end of 1 year with both the techniques. Flatus incontinence was the same at 12/36 months with both methods, but faecal urgency and faecal incontinence were less with the overlapping technique at the end of 1 year [11]. However, the studies included in this review were heterogeneous in outcome measures as they included both primi and multigravid women, with no mention of personal experience of physicians. Hence, either technique can be adopted as post-operative results are comparable and the surgeon should decide according to his/her expertise. Partial Thickness Tear of EAS (3a/3b) Partial thickness EAS tear can be approximated end to end by interrupted or 3–4 mattress stitches using 2-0 Polyglactin or 3-0 PDS. There are no systematic reviews on the best suture available for EAS repair; however, these fine sutures are not associated with tissue reaction. One RCT compared Polyglactin and PDS for morbidity related to sutures used at 6 weeks and bowel symptoms at 6 and 12 months and didn’t find any significant difference [9]. No studies are available comparing interrupted and mattress sutures for EAS repair; however, theoretically mattress sutures are associated with less risk of suture pull through circular muscle fibres and hence better approximation. Overlapping sutures are not recommended for partial thickness tears as they can cause undue tension over the stitches.

5.4.4 Perineal Muscles The perineal muscles should be approximated by running or interrupted sutures using 2-0 Polyglactin. Anatomical restoration of 2–3  cm perineal body helps to relieve tension off the sutures in the sphincter and also a proper distance between anus and vagina is maintained. 5.4.5 Vagina and Skin The vaginal mucosa and skin are approximated with a continuous non-locking and subcuticular suture, respectively, with 3-0 Polyglactin that is associated with lesser pain and discomfort. Interrupted sutures can be taken in case of uneven edges. It is mandatory to do a rectal examination after the repair to make sure that the sutures have not accidentally pierced through the anorectal mucosa. If a suture is felt through the anus, it should be removed as it may lead to a rectovaginal fistula later.

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5.4.6 Documentation It is very important to make an entry of details of the procedure in the operation theatre and should include the duration between delivery and procedure, mode of delivery, type of anaesthesia, type of repair and suture used for each layer. Sponge count is very important after the completion of the procedure, as the sponges after getting soaked with blood can get missed within the vagina and can present as retained sponges later.

6 Post-operative Care 6.1 Antibiotics Broad-spectrum antibiotics should be continued in the post-operative period for a total of 5 days to avoid post-operative wound infection and breakdown. Intravenous antibiotics (second generation Cephalosporin with Metronidazole) can be given in the initial 24–48 h followed by oral Amoxicillin-Clavulanic acid [12].

6.2 Analgesics It is very important to ensure adequate analgesia in the post-operative period as the pain and oedema associated with stitches can cause a lot of distress to the patient. Analgesics should be given in the form of NSAIDs; however, rectal route should be avoided if there is a complete perineal tear [10]. If needed, Paracetamol can be added with NSAIDs. Opioids are not advocated as they can cause constipation [10]. To reduce local oedema, ice packs can be applied 2–4 hourly for 10 min [13], which will help reduce the need for additional analgesics.

6.3 Bowel Care Some physicians prefer bowel confinement techniques in the immediate post-­ operative period to avoid bowel motion; however, it is not mandatory to keep the patient fasting in the post-operative period. The patient can be started on a low residue/fibre diet for 7 days to reduce the bulk of stools as well as to delay bowel emptying. Low residue diet includes white rice, refined flour, banana, eggs and vegetables without peel or seeds. Along with this diet, osmotic laxatives must be added for easy passage of stools in order to avoid stress on the stitches in the form of either syrup Lactulose 15 mL twice a day or PEG solution 17 g dissolved in 250 mL of water once a day [1, 3]. The patient should be advised to drink 2–3 L of water every day.

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6.4 Bladder Care Self-retaining urinary catheters must be kept for at least 12 h after repair, as the associated pain and oedema can lead to post-partum urinary retention [1, 6]. Once the catheter is removed, post-void residual urine can be measured to look for urinary retention.

6.5 Posture and Movement The patient should adopt positions that will decrease perineal oedema till 48 h after surgery. This includes lying supine or in a lateral position while breastfeeding. The patient should avoid sitting for long periods to avoid pressure over the stitches. For this, she can insert folded towels under the thighs. While opening bowels in the commode, the patient should sit with knees higher than hips and should lean forwards while putting elbows on her knees. The abdomen should be bulged out while keeping the spine straight. This position will avoid pressure over the perineum. The patient should avoid activities that increase intra-abdominal pressure such as Valsalva manoeuvre for a few months after surgery.

6.6 Pelvic Floor Exercises These increase the blood flow to the perineum and aid in early healing. All patients should be advised to initiate pelvic floor physiotherapy as soon as possible after the repair once the perineal pain subsides [14, 15]. The exercises should be done thrice a day, with squeezing and lifting the perineal muscles for at least 10 s and repeated 10 times in each session [14, 15]. A physiotherapist should be consulted in the post-­ partum period, as pelvic floor exercise can reduce the chance of incontinence. There is no proven role of the addition of biofeedback physiotherapy in improving sphincter function.

6.7 Wound Care It is very important to explain to the patient about perineal and hand hygiene to avoid wound infection and disruption. Perineum should be cleaned with water and pat dried with toilet paper. The patient should have a bath daily and must change sanitary pads regularly. Sitz baths with lukewarm water can be advised; however, one should not add bubbles or salt in the water as it may lead to the early dissolution of sutures. The patient should be taught to inspect the wound daily with the help of a hand mirror for any signs of wound breakdown.

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6.8 Debriefing The patient and her relatives must be debriefed in the ward about the post-operative advice, complications and future implications in the next pregnancy.

7 Prognosis About 60–80% of patients are asymptomatic after 1 year of EAS repair [3]. However, there is a 25% chance of wound breakdown and a 20% risk of wound infection during the first 6 weeks of repair [1]. The common long-term problems are dyspareunia, perineal pain, and flatal/faecal incontinence. The patient must also be told about the implication of sphincter tears on future pregnancy. In case of persistent anal incontinence or dysfunction, a caesarean section is advisable in the next pregnancy and the mode of delivery should be discussed and documented in antenatal records [3].

8 Follow-Up 8.1 Advice • Patient can have intercourse once she feels comfortable, but it should be avoided until stitches have completely healed. • Warning signs of complications should be told to the patient at the time of discharge such as redness, swelling, offensive discharge from the wound or flatus/ faecal incontinence and to report to the hospital if these symptoms occur.

8.2 Visit A follow-up appointment should be arranged at 6–12 weeks to assess wound healing and to detect wound complications [1, 14, 15]. Key Messages 1. Repair of third- and fourth-degree tears should be performed by an experienced obstetrician. 2. Ideally repair should be performed in an operating theatre, under regional or general anaesthesia with adequate lighting and appropriate instruments. 3. Figure of eight sutures should not be taken during the repair to avoid tissue ischaemia. 4. The anorectal mucosa should be repaired in an interrupted or continuous fashion using 3-0 Polyglactin.

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5. IAS should be repaired separately by taking either interrupted or continuous sutures without any overlapping. 6. For full thickness EAS tears, repair either by an overlapping or an end-to-end repair can be used; however, for partial thickness (all 3a and some 3b) tears, an end-to-end repair is preferable. 7. For EAS and/or IAS repair, either 3-0 PDS or 2-0 Polyglactin can be used. 8. The repair of the tear must finish with a rectal examination to rule out accidental piercing of anorectal mucosa and if suture is identified, it must be removed. Acknowledgement  The authors duly acknowledge Ms. Diya Reddy for her assistance in preparing the figures for this chapter.

References 1. ACOG.  ACOG practice bulletin No. 165: prevention and management of obstetric lacerations at vaginal delivery. Obstet Gynecol. 2016;128(1):e1–e15. https://doi.org/10.1097/ AOG.0000000000001523. 2. Queensland clinical guidelines perineal care. Guideline No. MN18.30-V4- R23. Queensland Health. 2020. 3. Royal College of Obstetricians and Gynaecologists. The management of third- and fourthdegree perineal tears. Green-top guideline No. 29. London: RCOG; 2015. www.rcog.org. uk/womens-­health/clinical-­guidance/management-­third-­and-­fourth-­degree-­perineal-­tears-­ greentop-­29. 4. Department for Health and Wellbeing. South Australian perinatal practice guideline  - third and fourth degree tear management 2018. Available https://www.sahealth.sa.gov.au/wps/wcm/ connect/1faf87004eedec4db635b76a7ac0d6e4/Third+and+Fourth+Degree+Tear+Managem ent_PPG_v5_1.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-­1faf87004eedec4d b635b76a7ac0d6e4-­n1mzbge. 5. Meister MR, Rosenbloom JI, Lowder JL, Cahill AG.  Techniques for repair of obstetric anal sphincter injuries. Obstet Gynecol Surv. 2018;73(1):33–9. https://doi.org/10.1097/ ogx.0000000000000521. 6. Harvey M-A, Pierce M, Alter J-EW, Chou Q, Diamond P, Epp A, et  al. Obstetrical anal sphincter injuries (OASIS): prevention, recognition, and repair. J Obstet Gynaecol Can. 2015;37:1131–48. https://doi.org/10.1016/s1701-­2163(16)30081-­0. 7. Sultan AH, Thakar R, Fenner DE, editors. Perineal and anal sphincter trauma: diagnosis and clinical management. London: Springer; 2007. 8. Nichols CM, Nam M, Ramakrishnan V, Lamb EH, Currie N.  Anal sphincter defects and bowel symptoms in women with and without recognized anal sphincter trauma. Am J Obstet Gynecol. 2006;194:1450–4. 9. Williams A, Adams EJ, Tincello DG, Alfirevic Z, Walkinshaw SA, Richmond DH.  How to repair an anal sphincter injury after vaginal delivery: results of a randomised controlled trial. BJOG. 2006;113:201–7. 10. Danish Association of Obstetrics and Gynaecology. Sphincter rupture: diagnosis, treatment and follow-up 2019. Available https://nfog.org/wp-­content/uploads/2019/03/190313-­obstetric-­ anal-­sphincter-­injury.pdf. 11. Fernando RJ, Sultan AH, Kettle C, Thakar R. Methods of repair for obstetric anal sphincter injury. Cochrane Database Syst Rev. 2013;12:CD002866. https://doi.org/10.1002/14651858. CD002866.pub3. 12. Auckland District Health Board guideline 2017. Perineal tears third and fourth degree (OASIS).

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13. East CE, Begg L, Henshall NE, Marchant PR, Wallace K. Local cooling for relieving pain from perineal trauma sustained during childbirth. Cochrane Database Syst Rev. 2012;5:CD006304. https://doi.org/10.1002/14651858.CD006304.pub3. 14. Obstetric Anal Sphincter Injury. NHS Liverpool women’s NHS foundation trust information leaflet. 2015. Available https://www.liverpoolwomens.nhs.uk/media/2932/obstetric-­anal-­ sphincter-­injury-­oasi-­mat_2019-­232-­v2.pdf. 15. Royal College of Obstetricians and Gynaecologists. Consent advice no 9. Repair of third and fourth degree tears following childbirth. 2010.

Prolonged Pregnancy P. Pallavee and Ashwini Vishalakshi L

1 Introduction Before the year 2012, various terminologies were used to describe pregnancies that reached or were near the expected date of delivery (EDD). Some of these were post-­ term, post-mature, prolonged pregnancy and post-dates. This created confusion because the definitions were not very clear. Moreover, the time period for ‘term’ pregnancy lasted from 37 to 42 weeks and the neonatal outcomes varied in the deliveries during this time period. A nomenclature proposed by the American College of Obstetricians and Gynecologists (ACOG) describes the early term as gestation from 37 0/7 weeks through 38 6/7 weeks of gestation, a full term from 39 0/7 weeks to 40 6/7 weeks, late-term as 41 0/7 weeks to 41 6/7 weeks of gestation and post-term from 42 0/7 weeks of gestation and beyond. The intention was to set out births happening at or beyond 37 0/7 weeks of pregnancy with greater validity [1]. Poor after-­ effects in newly born babies were lowest among straightforward gestations culminating at ‘full term’ [2].

2 Incidence The incidence of prolonged pregnancies varies between different ethnic groups. Overall, it has been reported to range from 4% to 14% with only 2–7% of pregnancies completing 43 weeks. In 2012, the incidence quoted by the Centers for Disease Control and Prevention (CDC) was 5.6% [3].

P. Pallavee (*) · A. Vishalakshi L Department of Obstetrics and Gynaecology, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth (Deemed-to-be-University), Puducherry, India e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_27

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Diagnosis of post-term pregnancy completely relies on the accurate determination of gestational age. One of the major problems with calculating the incidence is the error in accurately calculating the gestational age. For most patients, the gestational age is calculated according to the last menstrual period (LMP), which, as we all know, is not very reliable. This fact was emphasised in a study done by Gardosi et al. where the post-term delivery rate dropped from 9.5% to 1.5% when ultrasound was used to date the pregnancy instead of LMP [4].

3 Risk Factors and Pathogenesis The exact cause of post-term pregnancies remains unknown. It may be due to multiple factors that need to be coordinated for the initiation of labour. But various studies have identified many risk factors that can lead to post-term pregnancy. Genetic predisposition and race are the major risk factors contributing to post-term pregnancy. The others include primiparity, advanced maternal age, the male gender of the foetus and obesity [5]. Conditions like anencephaly, placental sulphatase deficiency and foetal adrenal disorders also contribute to post-term pregnancies by affecting the hypothalamic-pituitary-ovarian (HPO) axis that is involved in the initiation of labour. The initiation of labour requires the integration of complex mechanisms involving maternal, foetal and placental factors. Changes in the maternal tissue that prepare the uterus for parturition include cervical ripening, a surge in prostaglandin production, the formation of new myometrial gap junctions, and an increase in oxytocin receptor sensitivity. In the presence of various hormones secreted from the membranes and placenta, the prepared myometrium gets activated and regular uterine contractions start. The foetus contributes to this myometrial activation through various factors. These include the release of neurohypophysial hormones, activation of prostaglandin synthesis, increasing placental steroid hormone synthesis and involuntary distension of the uterus. At foetal maturity, the foetal hypothalamus and the placenta increase their secretion of corticotropin-releasing hormone (CRH). This acts on the foetal pituitary to secrete adrenocorticotropic hormone. Adrenocorticotropic hormone then causes the secretion of cortisol from the foetal adrenal gland. This leads to increased production of dehydroepiandrosterone (DHEA). Cortisol and DHEA increase oestrogen and prostaglandins that stimulate myometrial contractions resulting in labour. The initiation of labour may be delayed due to abnormalities in the various mechanisms mentioned above (in the foetal hypothalamic-pituitary-adrenal axis, abnormal setting of the placental clock or abnormalities in the myometrial activation/ cervical ripening). Examples include anencephaly and placental sulfatase deficiency. In the foetus with anencephaly, the foetal hypothalamo-pituitary-ovarianadrenal (HPOA) axis is not activated. The hypothalamus being absent or non-functional results in absence of secretion of CRH.  This results in post-term

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pregnancy when the amniotic fluid levels are normal. Placental sulphatase deficiency is an X-linked recessive disorder. The absence of the steroid enzyme leads to a lack of estriol due to which there is the absence of spontaneous labour.

3.1 Genetics and Race Maternal and paternal genes may contribute to 23–30% of the risk of late-term and post-term pregnancies [6]. Racial variations exist in the duration of pregnancy. It has been noted in various studies that the average gestational length of a pregnancy depends on the maternal racial origin. The paternal genes also contribute, but minimally so. Women who were born of post-term pregnancies, as per their own birth history, also had an elevated risk of lengthened gestation. The average gestational length varies among different races. It was found to be 39 weeks for pregnancies with a single foetus in South Asians and Black Caribbeans, whereas it was 40 weeks for Caucasians [7].

3.2 Obesity Pre-pregnancy BMI contributes significantly to prolonging the average gestational length. Women who are overweight have a 24% higher frequency of post-term pregnancy as compared to women with normal BMI. It increases to 37% and 52% in obese and severely obese women, respectively [8].

3.3 Recurrence There is a threefold increase in the frequency of post-term pregnancy in women who had a prior history of post-term pregnancy as compared to those who delivered at term. Following two post-term pregnancies, the risk is still higher [9]. A national cohort study done in the Netherlands followed up women who had singleton pregnancies and delivered between 37 and 42 weeks in their next pregnancy and reported a 15% recurrence risk of prolonged pregnancy. However, the maternal and perinatal outcomes did not differ much from that of the previous prolonged pregnancy [10].

4 Maternal Morbidity Post-term pregnancy can result in severe maternal morbidity mainly due to the interventions done to hasten the delivery, macrosomia or maternal anxiety associated with delayed delivery. Even though the incidence of complications is higher in induced pregnancies, spontaneous delivery is also shown to have more morbidity in women with post-term than full-term pregnancies.

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In post-term women who underwent induction of labour, the length of labour, incidence of prolonged second-stage labour, forceps use and caesarean delivery were all increased. The average rate of caesarean section in women induced for prolonged pregnancy was about 20%. The indication for caesarean section was usually nonreassuring foetal heart rate or cephalopelvic disproportion. The caesarean section rates increased rapidly after 42 weeks of gestation. This was reflected in a Norwegian study where the incidence was 19 per 1000 births at 41 weeks, and after 42 weeks it increased to 128 per 1000 births. There was also a high risk of chorioamnionitis [11]. Severe perineal laceration, infection and post-partum haemorrhage are other complications seen more often in post-term deliveries. The risk for all these complications is much higher in the nulligravida when compared to the multigravida. As the pregnancy progresses beyond 41 weeks, maternal anxiety increases significantly and most women prefer induction of labour as against expectant management.

5 Foetal Effects In prolonged pregnancies, the foetal risks are much higher as compared to maternal risks. Foetal risks are either because of placental dysfunction or because of the continued normal functioning of the placenta. Uteroplacental insufficiency results in oligohydramnios, reduced foetal growth, passage of meconium, asphyxia and stillbirth. In women with normal placental function, the foetus continues to grow in utero resulting in macrosomia which can lead to the occurrence of shoulder dystocia and trauma to the birth canal. Macrosomia is more common than growth restriction in post-mature foetuses. Most foetuses continue to grow in utero even after the date of EDD. A study by Eden et  al. showed that post-term pregnancies have a twofold increased risk for macrosomia. The risk of difficult operative delivery and shoulder dystocia resulting in neurological injuries was also increased in foetuses with macrosomia [12]. Other associated complications include cephalhematomas, fractures and severe maternal perineal injuries. Even though there is significant risk associated with macrosomia, ACOG advises against early induction of labour or caesarean section when foetal macrosomia is detected by ultrasound. This is because of the high margin of error associated with the estimation of foetal weight by ultrasound [13]. Uteroplacental insufficiency occurs because of placental senescence. The placental clock is set very early in gestation, that is, at the time of conception. After this set time period, the placenta undergoes degenerative changes like calcification, perivillous fibrin deposits, intervillous thrombosis, infarction, arterial thrombosis and arterial endarteritis [14]. Uteroplacental dysfunction occurs as a result of these degenerative changes that lead to intra-uterine growth restriction (IUGR) and oligohydramnios and sometimes even intrauterine death of the foetus. The incidence of small for gestational age infants dropped from 3.8% in post-term infants to 2.2% in term infants.

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Oligohydramnios seen in post-term pregnancies has been attributed to uteroplacental insufficiency which leads to foetal hypoxemia and reduction in blood flow to the foetal kidneys resulting in decreased urine output. But renal doppler studies done in post-term foetuses do not show any significant changes in the renal blood flow. Hence, the exact aetiology for oligohydramnios remains elusive. Regardless of the aetiology, oligohydramnios results in increased adverse perinatal outcomes. They are mainly because of cord compression and meconium staining of amniotic fluid (MSAF). MSAF is seen because of foetal hypoxemia leading to rectal sphincter relaxation. In the setting of oligohydramnios, the meconium fails to get diluted and remains thick and mucinous. This causes a higher incidence of meconium aspiration syndrome, poor Apgar scores, abnormal arterial blood gases and admission to the neonatal intensive care unit (NICU). In the presence of oligohydramnios, the incidence of meconium-stained amniotic fluid is 29%, which is much higher than in foetuses with normal amniotic fluid levels. Post-maturity syndrome occurs in 10–20% of foetuses in post-term pregnancies. Post-maturity should not be confused with the terminology ‘post-term’. Post-­ maturity describes how the baby functions and post-term just denotes the gestational age. The behaviour and appearance of the post-mature neonate are somewhat similar to those of the IUGR neonate. Some researchers also suggest it to be a manifestation of restricted growth in utero, even though the weight remains normal for gestational age. Features of post-mature infants include wrinkled and peeled skin because of wasting of subcutaneous fat and loss of lanugo and vernix caseosa. The newborn has an alert look with long nails. The skin and nails may be meconium stained. Clifford described the post-maturity syndrome and staged it according to the increasing severity of placental dysfunction. A long, lean infant with wrinkled and peeling skin is Stage I. In Stage II, in addition to the previous findings, there will be greenish meconium staining of amniotic fluid, foetal skin and placental membranes. Stage III is characterised by yellow-brown meconium staining, which is a sign of long-standing meconium, and this stage has a high incidence of foetal distress [15].

5.1 Perinatal Morbidity and Mortality Perinatal mortality is increased significantly in post-term pregnancies. Beyond 40 weeks of gestation, 60% of the deaths occur in the antenatal period before the onset of labour. In a large meta-analysis by Muglu et al. which included 15 million pregnancies, stillbirth rates ranged between 1.1 and 3.2 per 1000 pregnancies. As the duration of pregnancy progressed, the risk of stillbirth was seen to rise steeply with an incidence of 0.11 per 1000 pregnancies at 37 weeks to 3.18 per 1000 at 42 weeks gestation. The stillbirth risk increased by 64% when women continued their pregnancies up to 41 weeks, as opposed to those who gave birth at 40 weeks [16]. The increase in morbidity and mortality may be because there is an intrinsic difference between a normal term neonate and a post-mature neonate right from

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conception, as shown by a few studies. It has been found that post-term neonates had reduced levels of plasma cortisol as compared to normal term neonates who had high levels of cortisol post-delivery. Cortisol is required for the neonate to cope with the stress of labour. This marginal deficiency of cortisol levels may result in delayed onset of labour as well as increased risk of intrapartum hypoxia and stillbirths. Maternal and foetal risks were lowest at 39 weeks of pregnancy, after which adverse outcomes in the mother and the newborn and operative delivery rates increased. A study of a large Swedish database by Classuson et al. found that post-­ term gestations were related to an elevated incidence of neonatal seizures, meconium aspiration syndrome and Apgar scores of less than 4 at 5 min [17].

5.2 Long-Term Neonatal Outcomes The neonates delivered post-term had increased morbidity even in the post-natal period. There was an increased incidence of infections, sleep disorders and delay in attaining appropriate social milestones, especially in the first year of life. Some of them also showed an increased incidence of abnormal neurological development and epilepsy [18]. Their mental scores were also less compared to normal term neonates.

6 Interventions to Reduce Prolonged Pregnancy 6.1 Accurate Estimation of Gestational Age Early pregnancy ultrasound results in an accurate estimation of gestational age and may lead to a reduction in the number of inductions for post-term pregnancy. According to the ACOG and Society for Maternal-Fetal Medicine (SMFM), the best time to date the pregnancy is the first trimester, upto a gestational age of 13 weeks and 6 days. The gestational age calculated by measuring the crown rump length (CRL) in the first trimester has an accuracy of ±5–7 days. In in vitro fertilisation (IVF) pregnancies, gestational age and EDD calculation should be done by using the age of the embryo and the date of embryo transfer. Gestations lacking in an ultrasonographic evaluation that establishes the EDD before 22 0/7 weeks of pregnancy should be adjudged poorly dated [19].

6.2 Membrane Sweeping Membrane sweeping is an effective intervention to reduce the incidence of prolonged pregnancy [20]. It is a simple procedure done any time after 38 weeks and involves inserting one or two fingers through the cervix and separating the lower part of the foetal membranes from the lower uterine segment by rotating the finger through 360°. It leads to the release of prostaglandins with subsequent cervical ripening and initiation of labour. Maternal discomfort and vaginal bleeding are

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expected side effects which should be discussed during the counselling session regarding the advantages and disadvantages of sweeping of membranes. A recent Cochrane review update which looked into 44 randomised studies and published data on 6940 women from various resource settings found that membrane sweeping promoted the spontaneous onset of labour and decreased the requirement for formal induction of labour when compared with no or sham interventions. However, no noticeable differences were present in unassisted vaginal births, caesarean section rates, instrumental births and serious foetal and maternal side effects. The authors recommended further research to understand the ideal timing for doing the procedure and assess the effects of multiple or serial sweeps [21]. Other interventions like routine breast and nipple stimulation and sexual intercourse at term exerted nil influence in reducing the probability of having post-term pregnancy. The WHO and most other international society guidelines on induction of labour recommend offering sweeping of membranes to reduce the risk of post-term pregnancy [22–24]. In a major change from its previous guidance on offering membrane sweeping at 40 and 41 weeks for nulliparous and 41 weeks for multiparous women, the recent National Institute for Health and Care Excellence (NICE) guidance on induction of labour, 2021, advises to offer sweeping of membranes as early as 39 weeks after informed consent and to offer additional sweeps if it does not result in the spontaneous onset of labour.

7 Management of Prolonged Pregnancy The rate of stillbirth increases exponentially with gestational age after term. One of the key measures to reduce the incidence of stillbirth is the appropriate management of prolonged pregnancy. The two mainstays of management of low-risk pregnancy going beyond 40 weeks include expectant management or induction of labour. High-risk pregnant women who have obstetric or medical complications are usually delivered before 40 weeks.

7.1 Expectant Management Versus Induction of Labour There is no clear consensus on whether to wait for spontaneous labour or to induce prolonged pregnancies, which has been a matter of debate for long. Recently, a few good quality studies have shown the beneficial effects of elective induction for these pregnancies instead of adopting an expectant approach. However, the best time for induction needs to be investigated further. A large retrospective cohort study conducted in the United States included 442,003 low-risk nulliparous women who had delivered at term (between 39 and 42 weeks). They reported reduced caesarean section rates and better perinatal outcomes in terms of NICU admissions, Apgar scores and meconium aspiration in women who delivered at an earlier gestational age (e.g. 39 weeks) by induction compared to those who delivered at a later gestational age (at 40–42 weeks) [25].

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Significant changes in clinical practice were introduced after the results of the ARRIVE trial (A Randomized Trial of Induction Versus Expectant Management) were published. It was a multicentre trial conducted on 22,533 nulliparous women across 41 medical units in the United States. The eligibility criteria for the trial were nulliparous women who had reliable dating with no other medical or obstetric issues. The perinatal and maternal outcomes of induction of labour between 38 0/7 and 38 6/7 weeks were compared with those low-risk nullipara who were managed expectantly [26]. The main findings of the trial were the following: 1. The primary outcome, which was a composite of perinatal death and severe perinatal complications, was significantly less in women who underwent elective induction (4.3% in the induction group vs. 5.4% in the expectant group, P = 0.049). 2. The main secondary outcome was the caesarean delivery rate, which was significantly less with elective induction than in the expectant group (18.6% vs. 22.2%, P < 0.001). 3. Subgroup analysis did not show any significant differences in the results on the basis of race, ethnicity, maternal age, body mass index or Bishop’s score. The beneficial effects of elective induction demonstrated by the ARRIVE trial prompted the SMFM as well as the ACOG to endorse their findings and release statements recommending the use of elective induction of low-risk nulliparous women at 39 weeks of gestation, provided they met the eligibility criteria as stated in the ARRIVE trial. However, concerns have been raised regarding the universal implementation of this policy in clinical settings where the caesarean rates may be different from the centres where the trial was conducted. Also, the burden it might put on labour rooms where finding time slots for induction of these women with uncomplicated pregnancies, amongst those with justified indications for induction, might be challenging. The economic impact in terms of providing infrastructural support for such a strategy and also consideration of patient’s preferences are other areas of concern. The results of this study cannot, however, be generalised to multiparous women or those with post-caesarean pregnancy who are eligible for a trial of labour after caesarean (TOLAC), as they were not included in the study. The Swedish Post-term Induction Study (SWEPIS) was another multicentre, randomised trial, which intended to compare induction of labour at 41 weeks and expectant management with induction of labour at 42 weeks. The trial had to be shelved prematurely because of the increased risk of perinatal mortality in the expectant group [27]. A Cochrane review published in 2020 studied 34 randomised clinical trials which included a total of 21,000 women in high-income settings, who were either induced or managed expectantly at or beyond 37 weeks of gestation. It reported less number of perinatal deaths, lower caesarean section rates, NICU admissions and fewer babies with Apgar scores less than seven at 5 min in the induced arm. There was no

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significant difference between the groups for operative vaginal births, perineal trauma and post-partum haemorrhage. Subgroup analyses comparing outcomes in women induced at 41 weeks based on parity and state of cervix did not find any significant difference [28]. Another argument that tilts the balance in favour of induction of labour, as opposed to expectant management, is that long-term educational outcomes of children born from mothers who were induced at term by 39–40 weeks did not differ from those whose mothers were expectantly managed [29].

7.2 Expectant Management Expectant management or ‘wait and watch’ policy is often requested by patients as well as favoured by treating physicians who are worried about the risks posed by induction and prefer a spontaneous onset of labour. In this approach, the low-risk pregnant woman is allowed to continue her pregnancy beyond the estimated date of delivery till a predetermined gestational age is reached or the foetal assessment becomes non-reassuring. Though the risk of perinatal death is more when compared to elective induction in prolonged pregnancies, the absolute risk is still low (3 per 1000 pregnancies). Informed consent has to be obtained from women opting for expectant management. They need to be counselled regarding the following points: 1. Risk of neonatal morbidity and mortality increases when pregnancy is prolonged. 2. Risk of caesarean delivery and instrumental birth is increased in these pregnancies. 3. Antepartum foetal surveillance may not predict or prevent foetal demise in prolonged pregnancy.

7.2.1 Antepartum Foetal Surveillance Studies are inconclusive regarding the frequency of antepartum foetal assessment and the methodology to be used for it. However, foetal surveillance is preferably done twice weekly between 41 and 42 weeks and commonly includes checking the amniotic fluid levels and foetal cardiotocography. Foetal doppler has not been shown to be beneficial for monitoring these pregnancies as the pathogenesis of placental insufficiency in prolonged pregnancy is different from that of foetal growth restriction [30].

7.3 Timing of Induction of Labour As more and more good quality evidence is being reported regarding the merits of elective induction in prolonged pregnancy, international societies and the WHO have updated their guidelines to be incorporated into clinical practice. The WHO guidelines (2018) recommend induction of labour in a woman whose gestational age has been confirmed to have reached 41 weeks of pregnancy. They do

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not recommend induction of labour in low-risk gestations of less than 41 weeks. The new NICE guidelines on induction of labour released in November 2021 recommend offering induction at 41 weeks of gestation for uncomplicated singleton pregnancies replacing its previous advice of offering induction between 41 and 42 weeks. Induction of labour can be offered at 39 weeks to those who are at higher risk of complications like hypertensive disorders. The ACOG suggests induction of labour for gestations between 42 0/7 and 42 6/7 weeks for those on expectant management as being appropriate and also advises to consider induction between 41 0/7 and 42 0/7 weeks of pregnancy. It also gives a go-ahead to induction of labour at or more than 39 weeks for low-risk nulliparous women, if they satisfy the eligibility criteria of the ARRIVE trial.

7.4 Cervical Ripening A cervix that is unfavourable for induction of labour can lead to higher rates of operative delivery. When the cervical assessment indicates a Bishop’s score less than 6, the cervix needs to be ripened to respond better to induction of labour. Cervical ripening, which makes the cervix soft, easily dilatable and effaced, increases the rate of successful induction of labour. At present, there are no recommendations about a particular ripening agent to be used for prolonged pregnancies. Nitric oxide is one of the final metabolic mediators in the ripening cascade of the human cervix. Nitric oxide donors have been evaluated as potential ripening agents in various studies [31]. A double-blinded placebo-controlled randomised trial assessed the outpatient use of cervical ripening with 40  mg vaginal isosorbide mononitrate (IMN) given to nulliparous women with prolonged pregnancies at 41 0/7, 41 2/7 and 41 4/7 weeks during hospital visits. Subsequently, they were admitted and induced by 41 5/7 weeks if they had not entered into spontaneous labour. The primary outcome was the caesarean section rate which was similar in both groups. Those who received isosorbide mononitrate experienced more side effects than the placebo group [32]. Prostaglandins like dinoprostone in the form of vaginal gels or inserts are used commonly as ripening agents when the Bishop’s score is less than 6. Mechanical dilators like Foley’s catheters can be used where the risk of hyperstimulation is more, as well as in post-caesarean pregnancies posted for TOLAC where prostaglandins need to be used with caution. The MAGPOP (Mechanical cervicAl ripeninG for women with PrOlonged Pregnancies) trial was conducted in 15 maternity units across France and randomised women with prolonged pregnancies into two groups, one in which, cervical ripening was induced using silicone double balloon catheters and the other in which a vaginal dinoprostone slow-release system was used. They found no difference in their primary outcome which was the rate of caesarean deliveries for nonreassuring foetal status. The time to the delivery interval was shorter in the dinoprostone group but lesser additional analgesia was required in the balloon catheter method. No difference was noted in other delivery, maternal or neonatal

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outcomes. The authors concluded that there was no justification for using a mechanical method over a pharmacological method for cervical ripening in prolonged pregnancies [33].

8 Role of Ultrasound for Prediction of Delivery Outcomes in Prolonged Pregnancy Along with maternal factors like parity and body mass index, assessment of cervical length using ultrasound after the term has been found to predict the spontaneous onset of labour within a week’s time. It also predicts the chance of successful induction of labour and the risk of caesarean birth in prolonged pregnancy. Cervical length assessment by ultrasound was found to be a better predictor of induction-delivery interval and successful vaginal birth within 24 h when compared to Bishop’s score or digital assessment of cervical length in prolonged pregnancy [34].

9 Future Research in Prolonged Pregnancy Decreased PI-middle cerebral artery is a consequence of mild hypoxia in prolonged pregnancy, and the decrease of PI-UA, especially in large foetuses, may be a sign of cardiac function deterioration. In these conditions, normal CPR does not indicate that the foetus is not in danger. Type of aortic isthmus (AoI) blood flow velocity waveforms should be evaluated as an adjunct for foetal surveillance in prolonged pregnancy [35]. A multitude of studies have tipped the balance in favour of induction of labour in prolonged pregnancy instead of adopting an expectant approach. However, further studies are required to assess the feasibility of accepting this policy universally in different resource settings, the most appropriate time for induction and neonatal outcomes of early induction in the long term. Genetic studies can give further insight into hereditary predisposition for prolonged pregnancy and help in better management of these pregnancies.

References 1. American College of Obstetricians and Gynecologists. Definition of term pregnancy. Committee Opinion No. 579. Obstet Gynecol. 2013;122:1139–40. 2. Reddy UM, Bettegowda VR, Dias T, Yamada-Kushnir T, Ko CW, Willinger M. Term pregnancy: a period of heterogeneous risk for infant mortality. Obstet Gynecol. 2011;117:1279–87. 3. Martin JA, Hamilton BE, Osterman MJK, Curtin SC, Mathews TJ. Births: final data for 2012. National vital statistics reports, vol. 62. Hyattsville: National Center for Health Statistics; 2013. 4. Gardosi J, Vanner T, Francis A. Gestational age and induction of labour for prolonged pregnancy. BJOG. 1997;104(7):792–7.

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5. Usha Kiran TS, Hemmadi S, Bethel J, Evans J. Outcome of pregnancy in a woman with an increased body mass index. BJOG. 2005;112(6):768–72. 6. Laursen M, Bille C, Olesen AW, Hjelmborg J, Skytthe A, Christensen K.  Genetic influence on prolonged gestation: a population-based Danish twin study. Am J Obstet Gynecol. 2004;190:489–94. 7. Patel RR, Steer P, Doyle P, Little MP, Elliott P. Does gestation vary by ethnic group? A London-­ based study of over 122,000 pregnancies with spontaneous onset of labour. Int J Epidemiol. 2004;33(1):107–13. 8. Ross N, Sahlin L, Ekman-Ordeberg G, Kieller H, Stephansson O. Maternal risk factors for post-term pregnancy and cesarean delivery following labor induction. Acta Obstet Gynecol Scand. 2010;89:1003–10. 9. Kistka ZA, Palomar L, Boslaugh SE, de Baun MR, de Franco EA, Muglia LJ. Risk for post-­ term delivery after previous post-term delivery. Am J Obstet Gynecol. 2007;196:241. 10. Kortekaas JC, Kazemier BM, Ravelli AC, et  al. Recurrence rate and outcome of post-term pregnancy, a national cohort study. Eur J Obstet Gynecol Reprod Biol. 2015;193:70–4. 11. Caughey AB, Bishop JT. Maternal complications of pregnancy increased beyond 40 weeks of gestation in low risk women. J Perinatol. 2006;26:540–5. 12. Eden RD, Seifert LS, Winegar A, Spellacy WN.  Perinatal characteristics of uncomplicated post-date pregnancies. Obstet Gynecol. 1987;69:296–9. 13. American College of Obstetricians and Gynecologists. Management of post-term pregnancy. Practice Bulletin No. 55. Obstet Gynecol. 2004;104(3):639–46. 14. Smith SC, Baker PN.  Placental apoptosis is increased in post-term pregnancies. BJOG. 1999;106(8):861–2. 15. Clifford S. Post-maturity with placental dysfunction: clinical syndrome and pathologic findings. J Pediatr. 1954;44(1):1–13. 16. Muglu J, Rather H, Arroyo-Manzano D, Bhattacharya S, Balchin I, Khalil A, et al. Risks of stillbirth and neonatal death with advancing gestation at term: a systematic review and meta-­ analysis of cohort studies of 15 million pregnancies. PLoS Med. 2019;16(7):e1002838. 17. Clausson B, Cnattingius S, Axelsson O. Outcomes of post-term births: the role of fetal growth restriction and malformations. Obstet Gynecol. 1999;94:758–62. 18. Ehrenstein V, Pedersen L, Holsteen V, Larsen H, Rothman KJ, Sorenson HT. Post-term delivery and risk for epilepsy in childhood. Pediatrics. 2007;119:554–61. 19. American College of Obstetricians and Gynecologists. Methods for estimating the due date. Committee opinion No 700. Obstet Gynecol. 2017;129:150–4. 20. de Miranda E, van der Bom JG, Bonsel GJ, Bleker OP, Rosendaal FR. Membrane sweeping and prevention of post-term pregnancy in low-risk pregnancies: a randomised controlled trial. BJOG. 2006;113(4):402–8. 21. Finucane EM, Murphy DJ, Biesty LM, Gyte GML, Cotter AM, Ryan EM, Boulvain M, Devane D. Membrane sweeping for induction of labour. Cochrane Database Syst Rev. 2020;2:2. 22. World Health Organization. WHO recommendations: induction of labour at or beyond term. Geneva: World Health Organization; 2018. Licence: CC BY-NC-SA 3.0 IGO. 23. American College of Obstetricians and Gynecologists. Management of late-term and post-­ term pregnancies. Practice Bulletin No. 146. Obstet Gynecol. 2014;124:390–6. 24. Wise J. NICE recommends inducing pregnant women one week earlier. BMJ. 2021;373:1358. 25. Cheng YW, Kaimal AJ, Snowden JM, Nicholson JM, Caughey AB. Induction of labor compared to expectant management in low-risk women and associated perinatal outcomes. Am J Obstet Gynecol. 2012;207(6):502. 26. Grobman WA, Rice MM, Reddy UM, Tita ATN, Silver RM, Mallett G, et al. Labor induction versus expectant management for low-risk nulliparous women. N Engl J Med. 2018;379:513–23. 27. Wennerholm U, Saltvedt S, Wessberg A, Alkmark M, Bergg C, Wendel SB, et al. Induction of labour at 41 weeks versus expectant management and induction of labour at 42 weeks (Swedish Post-term induction Study. SWEPIS): multicenter, open label, randomized superiority trial. BMJ. 2019;367:16131.

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28. Middleton P, Shepherd E, Morris J, Crowther CA, Gomersall JC.  Induction of labour at or beyond 37 weeks gestation. Cochrane Database Syst Rev. 2020;7(7):CD004945. 29. Werner EF, Schlichting LE, Grobman WA, Viner-Brown S, Clark M, Vivier PM. Association of term labor induction vs. expectant management with child academic outcomes. JAMA Netw Open. 2020;3(4):e202503. 30. Kauppinen T, Kantomaa T, Tekay A, Mäkikallio K. Placental and fetal hemodynamics in prolonged pregnancies. Prenat Diagn. 2016;36(7):622–7. 31. Bollapragada SS, MacKenzie F, Norrie JD, Eddama O, Petrou S, Reid M, et al. Randomised placebo-controlled trial of outpatient (at home) cervical ripening with isosorbide mononitrate (IMN) prior to induction of labour-clinical trial with analyses of efficacy and acceptability. The IMOP study. BJOG. 2009;116:1185–95. 32. Schmitz T, Fuchs F, Closset E, Rozenberg P, Winer N, Perrotin F, et al. Outpatient cervical ripening by nitric oxide donors for prolonged pregnancy. Obstet Gynecol. 2014;124(6):1089–97. 33. Diguisto C, Le Gouge A, Arthuis C, Winer N, Parant O, Poncelet C, et al. Cervical ripening in prolonged pregnancies by silicone double balloon catheter versus vaginal dinoprostone slow release system: The MAGPOP randomised controlled trial. PLoS Med. 2021;18(2):e1003448. 34. Rozenberg P, Chevret S, Chastang C, Ville Y.  Comparison of digital and ultrasonographic examination of the cervix in predicting time interval from induction to delivery in women with a low Bishop score. BJOG. 2005;112(2):192–6. 35. Shatylovych K, Markin L, Sklyarova V. VP43.03: fetal and placental hemodynamic changes in prolonged pregnancy. Ultrasound Obstet Gynecol. 2021;58:276–7. https://doi.org/10.1002/ uog.24622.

Preterm Labour Savita Somalwar, Anuja Bhalerao, and Nikita Vijay

1 Introduction World Health Organization (WHO) and International Federation of Gynecologists and Obstetricians (FIGO) define Spontaneous Preterm Labour as ‘Labor resulting in birth before 37 completed weeks (259 days) of gestational age, based on the first day of last menstrual period’. Globally every year, an estimated 15 million babies are born preterm (before 37 completed weeks of gestation), and this number is increasing. Preterm birth complications are the leading cause of death among children under 5 years of age and were responsible for approximately 1 million deaths in 2015 [1]. Three-quarters of these deaths could be prevented with current, cost-effective interventions. The rate of preterm birth ranges from 5% to 18% of babies born across 184 countries, and in India prevalence is 23.3% [2]. India contributes to the highest incidence in the world with over 3,500,000 annual preterm births [3]. Prematurity can lead to increased neonatal mortality and short-term and long-­ term morbidity because of organ immaturity. Recent improvement in neonatal care has resulted in increased survival but has also led to more morbidities in neonates. Morbidities include neurocognitive impairment, cerebral palsy, hearing impairments, intellectual or motor disabilities, bronchopulmonary dysplasia and retinopathy of immaturity which can contribute to lifelong disability. There is a difference in terminologies preterm labour and preterm birth. Preterm labour is the onset of labour pains after the period of viability and before 37 weeks of gestational age and preterm birth is delivery after the period of viability and before 37 weeks of gestation. Preterm labour may not always lead to preterm birth.

S. Somalwar · A. Bhalerao (*) · N. Vijay Department Obstetrics and Gynaecology, NKP Salve Institute of Medical Science, Nagpur, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_28

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Out of all preterm deliveries, one-third deliveries are observed with intact membranes, another third are a result of preterm premature rupture of membranes and the remaining third result from delivery of a preterm baby due to maternal or foetal conditions such as preeclampsia, eclampsia, antepartum haemorrhage and intrauterine growth restriction.

2 Definition 1. Preterm birth: Birth after the period of viability and before 37 completed weeks of gestation. The period of viability differs in different regions depending upon efficient neonatal intensive care units. Recently birthweight more than or equal to 500 g has been included in preterm statistics in many developed and developing countries. The lowest limit of foetal maturation compatible with extrauterine survival is the threshold of viability. In the United States, the threshold of viability is between 20 and 26 weeks (peri viable births) while the gestational age of viability is 24 weeks in the United Kingdom, and in India it is 28 weeks (Table 1). 2. Suspected/threatened preterm labour: Presence of uterine contractions without cervical dilatation. 3. Diagnosed preterm labour: Presence of uterine contractions with cervical changes. 4. Established preterm labour: Uterine contractions and progressive cervical dilatation of more than 4 cm [4]. Table 1  Showing subgroups of prematurity Country India (FOGSI) and WHO United States of America

Subgroups of prematurity Extremely preterm—20 h in nulli and > 14 h in multi) is not an indication for 1. CS 2. Slow but progressive labor in first stage be augmented by oxytocin and should not be an indication for CS 3. 6 cm dilatation be considered as the threshold for the active phase 4. Definition of active phase arrest for opting C-section: Labor >6 cm dilatation with membrane rupture with >4 h of adequate contractions (>200mVU) or >6 h of inadequate contractions and no cervical change 5. 2nd stage: absolute fixed maximum length not identified for opting C-section 6. The arrest of second stage definition: At least 2 h of pushing in multiparous women or 3 h of pushing in nulliparous women Even longer duration may be appropriate in epidural analgesia 7. Opting operative vaginal delivery under-trained hands 8. Manual rotation of the head in case of malposition in the second stage be considered before delivery as safe 9. Amnio-infusion be tried for repetitive variable fetal HR deceleration Labor induction 1. Induction at 41 weeks Before 41 weeks 0/7 used only for any maternal-fetal indication 2. Cervical ripening method be used with unfavorable cervix cases 3. Induction failure: (in latent phase): longer duration up to 24 h or longer can be allowed if maternal and fetal condition permits General measures 1. CS for large for gestation age: 4.5 kg with diabetes only, not in nondiabetics 2. Twin pregnancy with first cephalic should be tried for vaginal birth 3. Attempts to avoid excessive maternal weight gain be opted in the ante-natal period

Grade 1B 1B 1B 1B

1C 1B

1B 1B 1A 1A 1B 1B

2C 1B 1B

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(c) Position, (d) Mobility, (e) Pain management. (f) Separate cabins for delivery, etc. The team should take care to maintain the sanctity of women in the late stages of labor. Allowing the partner or one of the relatives inside can make the parturient more comfortable in her painful time. Cochrane meta-analysis of 12 trials on 15,000 women reports that continuous presence of support personnel improves patient satisfaction and is associated with a statistically significant reduction in the C-section rates without any harm [7]. The study by Emily Lombard from Saint Joseph hospital Chicago II reports reduction in Nulliparous, term singleton vertex presentation C-section rate from 35 to 29.4% over 1 year period following the ACOG based recommendations of labor. 3. Use of partograph/Labor care guide by the labor room team to display the progress of labor with the maternal and fetal condition on a single graph page helps not only in a timely correct decision on mode of delivery considering the mother-­ fetal dyad but also guides the timely referral to the higher center by medical officers/midwives working at peripheral centers in low resource settings. Following the 2018 global recommendations on intrapartum care, the WHO revised the partograph based on fresh evidence. The WHO released new tool called “Labour care guide” and manual to support the healthcare provided to use it amending the durations, triggers for clinical interventions, and emphasis on respectful maternity care [6] (Fig. 2). Major changes in labour care guide from erstwhile partograph are: (a) The 1 cm/h alert line and its corresponding action line have been replaced with evidence-based time limits at each centimeter of cervical dilatation during the active phase of labor. (b) Active phase starts at 5 cm cervical dilatation instead of 4 cm or less earlier. (c) Second stage is now monitored intensively in a new section introduced and supportive care interventions. (d) Strength of uterine contractions is now no longer monitored as it is quite subjective and difficult to quantify clinically. 4. Improving intrapartum procedural skills of doctors is a must to reduce the primary C-section rates. The following measures should be utilized for training the residents as well as the labor room staff. (a) Skill labs training before working on real-world patients, (b) Hands-on workshops on specialized advanced mannequins, (c) Dummy patients, role plays, (d) Drills, (e) Performance under supervision. The skills actually should be taught during the residency period as per the evidence-based guidelines in step-by-step manner for better vaginal delivery outcomes like:

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Fig. 2  WHO labour care guide

• VBAC trial: Repeat C-section is the major contributor to the increasing C-sections as well as responsible for the complications. Indications, relative and absolute contraindications for the trial of labor and vaginal

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birth after one or two cesarean sections should be clear. Trial in different ­scenarios needs risk-benefit analysis and doctors must be able to explain it to their patients to allow trial of labor in selected cases. Version (External and internal): Malpresentation is another common reason for the C-section after fetal distress. Breech being commonest ­malpresentation where external cephalic version near 36–37  weeks of gestation can be opted safely in selected group cases. Art of version has been almost lost in this modern era. Instrumental delivery: The second stage C-sections are the most frustrating as women bear the full labor pains and then end up in cesarean. Instrumental delivery includes ventouse and forceps which can be utilized safely for selected cases as an alternative to C-section. Ventouse is safe and easy to learn and has fewer complications but takes a bit of time, while forceps are best for the second stage fetal distress cases. Skill needs to be learned properly to reduce the relative complications and tackle them if it occurs. Low and outlet forceps are the two operative delivery options that can be safely opted for second-stage delay, fetal distress, cut short the duration of second stage in high-risk women. Interpreting the Cardiotocograph findings: Fetal distress is the most common indication for the C-section. Resource-limited settings use intermittent auscultation but now CTG is being utilized for electronic monitoring of fetal heart rate in relation to uterine contractions. Understanding the graphical record especially the various decelerations and choosing the mode of delivery based on that need to be learned to reduce the unnecessary C-sections just based on findings of decelerations. Obstetricians should learn from their own experience from the CTG findings and the delivery outcomes and improvise. Partograph filling: Residents and staff must be made habitual of using the partograph or the labor care guide simultaneously with labor progress. Occasionally, it is either not used or being filled just at the end to complete the record. It can guide the various interventions timely which can improve the labor outcome and reduce the chances of C-section to some extent. Twin vaginal delivery: Multiple pregnancies are associated with the malpresentation and malpositions. First cephalic should be given full chance to deliver vaginally and second baby even if malpositioned as transverse or breech can be taken care of by internal podalic version. It is important to make the patient party believe in obstetrician and confidence should be built from the antenatal period itself. Antenatal counseling of women and family members targeting different periods of pregnancy, early, late pregnancy, intrapartum, post-partum along with proper consent taking to avoid medico-legal implications. Discussion about appropriate weight gain, diet, and exercise initially and periodically throughout pregnancy.

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• Tackling the upcoming obstetricians at their residency level will improve the future primary C-section rates. Medical college teachers must take this responsibility seriously and train the residents to avoid the primary C-sections as much as possible. Institutional protocols be formed and major recommendations and guidelines be followed. It ideally be considered as core section in the post-graduate teaching module/curriculum of obstetrics and gynecology. • National and state-level organizations must carry out hands-on workshops to re-sensitize at necessary intervals and inform about any new updates especially the peripheral healthcare medical officers and staff involved in maternity services. Protocols be framed based on our Indian scenario, culture, and resource setting and be used nationwide. Doctors need to know the possibilities, indications, and emphasize the importance of safe natural birth since the women are booked with them to facilitate only truly medically indicated C-sections. 5. Labor analgesia: Fear of pain and anxiety are the two main factors responsible for opting for C-section by the modern generation of working women. Hospitals with facilities must use and encourage painless natural childbirth using labor analgesia in the selected cases. Thus, informing women about this facility and sharing the responses of the women who opted for this can be helpful. Non-clinical interventions are defined as interventions applied independently of a clinical encounter between a healthcare provider and patient care. Apart from the clinical expertise and developing excellence in understanding the labor and managing it in a naturalistic way in hospital settings, many non-clinical measures are required to communicate the same to the whole healthcare team working outside hospitals so that community mandate be switched in favor of vaginal delivery instead of C-section [21]. The benefits of natural vaginal mode compared to abdominal route, related immediate and long-term risks, for both mother and fetus is required to be communicated starting from the preconception period and throughout antenatal period. Fear, anxiety, hesitation can best be overcome in the antenatal period itself by communication and tolerance has to be developed slowly to bear the painful labor and to make women accept the vaginal route on her own. Cochrane review conducted in 16 different countries, defines that Non-clinical interventions to reduce unnecessary C-sections can be divided into three sections. • Interventions targeted at women, • The intervention targeted at healthcare professionals, • Interventions targeted at health organizations, facilities, or systems. 1.

Recommendation (low certainty evidence) includes. (a) Childbirth training workshops: antenatal education about natural childbirth, (b) Nurse-led applied relaxation training, (c) Psychosocial couple counselling program—emotional support, conflict management to foster positive joint parenting,

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(d) Allaying fear of childbirth by psychosocial support—information about fear and anxiety, individual reactions, hospital routines, etc. (e) Computer-based decision aids (information program, decision analysis) can aid, the Second opinion regarding the decision of C-section, 2. Recommendation for healthcare providers: Apart from implementing evidence-­ based clinical practice guidelines, it is important to reanalyze the happening and outcomes by opting the new models of care as per the problems identified. “Audit” and feedback, and innovating new models of maternity care provide the best opportunity for reducing C-section rates. (a) Audits of indications for C-section birth is one best policy to restrain rate to real required ones. The review suggested that the C-section rate not only reduced by 13% with audits and feedback but also further by 27% when second opinion and culture change were involved [8]. For global audit purposes, it is important to have standardized acceptable classification. This one barrier is being covered by Robson’s classification system accepted by the WHO to monitor and compare the C-section rates and trends. Robson’s 10 group classification was introduced in 2001, based on simple obstetric characteristics (parity, prev CS, gestational age, onset of labor, fetal presentation, number of fetuses), without needing the indication of C-section [9]. The main advantage of classification is that self-tailored and justified indications which have potential subjectivity are not part of it. The WHO has said it a complete perinatal classification and released an implementation manual for correct use of Robson’s classification for healthcare teams. As per them, it should be used globally for assessing, monitoring, and comparing C-section rates within healthcare facilities over time and between facilities [10]. Midwives/healthcare workers can be taught this and there is no need for a specialist to define it (Fig. 3). Users have suggested to add indications of C-section within each group in a standardized manner (Anderson Model) or merging and subgrouping in Robson’s and therefore need to be researched [11]. It is very much important that the whole world uses the same classification system to know the actual trends and fields to be worked up or and interventions can be designed [12, 13]. Robson’s classification is good for the low-resource settings audits (Fig. 3). It’s simple, robust, and flexible to evaluate the impact of management changes and for audit purposes. The inherent advantage of classification is that it allows self-validation as few groups act as controls; an example is gr −9; women with fetus in transverse/oblique lie which should be around 1% of all females admitted for delivery and have almost 100% C-section. Abnormal values in such places indicate wrong data collection [14–16]. The WHO expects that this classification will identify and analyze the group which contributes most and least to C-section rates and compare the quality of care and clinical management practices in these two groups/units.

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Fig. 3  Robsons classification of caesarean section

(b) Innovative maternity care models: Collaborative midwifery-obstetrician model of care where care is provided primarily by midwives with 24  h backup from an obstetrician who provides in-house labor and delivery coverage without other competing clinical duties (context-specific recommendations). This care model addresses intrapartum C-sections primarily. Quality improvement models at medical colleges and corporate sectors: Model including labor analgesia, written reports of CTG in the medical record and subsequent auditing its results. It helps in improving the orientation and establishes a learning curve for the resident doctors in interpreting the CTG graphs. “Plan—do—study—act cycles” for nurses and resident orientation. Daily rounds—coronating discussions and monthly feedback among the healthcare team. Quantifying the departmental and individual provider C-section rates with their indications and analyzing them side by side with other institutions or national/global rates can help to find out the responsible team and the reasons behind it. Small maternity centers, nursing homes, and other facilities in the private sector be guided and supervised by the audit teams to follow the national guidelines and not to choose the C-section just on personal or patient request.

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3. Recommendation for healthcare organizations: Policymaking and changes are required in the healthcare government section. (a) Financial strategies like equalizing physician fees for a vaginal birth and C-section rate require rigorous research. (b) Legal reforms to avoid the pressures of medico-legal aspects and opting truly required option. C-section association with malpractice premiums and caps on damages is seen and our focus on reducing the primary C-sections be prioritized, which in turn would lower the repeat C-sections. (c) Support policies: Separate facilities for maternity and neonatal services provision. Improvements and incentives to promote the utilization of public health facilities for maternity healthcare with trained staff availability. Provision of respectable maternity care so that fear, anxiety, hesitation associated with vaginal births can be curtailed. Allowing one birth attendant with the parturient at the time of labor can be one support policy. (d) Education, training, managerial strategies be defined and implemented to change the behavior of physicians, pregnant women, relatives (especially husbands) regarding opting the mode of delivery. Free natural birth training and promotion of a painless childbirth policy can be options to reduce the C-sections just based on anxiety and fear. Making the involvement of specialist must for defining the C-section indication with evidence can to some extent help [17]. (e) FOGSI recommends setting up a cloud-based registry linked to websites to collect hospital data using the WHO-recommended Robson’s classification as the first step. (f) The study by Bhartia et al. in regard to the urban private setting for C-­section, concludes that moving to full-time specialist doctors, joining a collaborative, truthful data collection resources, and perseverance are the best adoption policy towards medically justifiable C-section rate [17]. Possible barriers in adopting non-clinical interventions and the suggested options for implementing and making strategies for the same have been defined by WHO in detail and summary is shown in Table 2 [18].

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Table 2  WHO non-clinical intervention Implementation recommendations Barrier or constraints Patient/community level Lack of understanding of values of recommended maternity care practices Health-care professional factors Resistance of health care providers to changing their entrenched c-section practices

Lack of clear hierarchical structure among senior consultants Patients demands that hinder adherence

Health-care organization or system factors Lack of human resources Lack of space Lack of essential supplies

Lack of healthcare information management systems Guideline factors Inconsistency of guidelines. Recommendations may not be congruous with the customs and norms of society

Proposed strategy for implementation Community-level sensitization activities to disseminate information, risk of C-section, and benefits of adhering to recommended practices Involve local opinion leaders Provide information and training by medical colleges and institutions To implement evidence-based strategies Successful strategies be documented for other implementers Develops local case-specific protocol to be reviewed from time to time Organize teams with a shared goal Patient education materials The training targeted workers to provide patient education Redistribution or resources, task shifting Gradual change acceptable with strategic budgetary planning. (long-term sustainable) Senior consultant to provide the second opinion Devise strategies to improve supply chain management Electronic records and registers Provide incentives to record needed information Updation of latest evidence-based guidelines apply to all societies, not just borrowing from the western world Adding explanations and justifications to adopt

3 Summary Changing the cultural beliefs and attitudes of the population and care providers regarding C-section reduction is a real challenge. A holistic approach of individual clinician practices updated management guidelines, systemic approaches at an organizational and regional level, with minimal medico-legal pressures. The WHO clearly states that C-sections be done only when medically indicated. International healthcare community has considered that the ideal rate for cesarean sections should be kept between 10 and 15% because it has been seen that when rate rises above 10% there is no evidence on improving maternal fetal mortality [19, 20]. Despite defining the ideal cesarean rate, the WHO also states that it is important to ensure abdominal delivery be provided to women in need and not just focus on achieving rates.

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References 1. World Health Organization. WHO statement on caesarean section rates. Geneva: World Health Organization; 2015. http://www.who.int/reproductivehealth/publications/maternal_perinatal_ health/cs-­statement. Accessed 31 May 2018. (WHO/RHR/15.02). 2. Barber EL, Lundsberg LS, Belanger K, Pettker CM, Funai EF, Illluzzi JL. Indication contributing to increasing caesarean delivery rate. Obstet Gynaecol. 2011;118:29–38. 3. Sandall J, Tribe RM, Avery L, et  al. Short-term and long-term effects of caesarean section on the health of women and children. Lancet. 2018;392:1349–57. https://doi.org/10.1016/ S0140-­6736(18)31930-­5. http://www.ncbi.nlm.nih.gov/pubmed/30322585. 4. Boerma T, Ronsmans C, Melesse DY, et al. Global epidemiology of use of and disparities in caesarean sections. Lancet. 2018;392:1341–8. https://doi.org/10.1016/S0140-­6736(18)31928-­7. http://www.ncbi.nlm.nih.gov/pubmed/30322584. 5. Caughey AB, Cahill AG, Guise J-M, Rouse DJ. Safe prevention of primary caesarean delivery. Am J Obstet Gynecol. 2014;123:693–711. https://doi.org/10.1016/j.ajog.2014.01.026. 6. Hofmeyr GJ, Bernitz S, Bonet M, Bucagu M, Dao B, Downe S, Galadanci H, Homer CSE, Hundley V, Lavender T, Levy B, Lissauer D, Lumbiganon P, McConville FE, Pattinson R, Qureshi Z, Souza JP, Stanton ME, ten Hoope-Bender P, Vannevel V, Vogel JP, Oladapo OT. WHO next-generation partograph: revolutionary steps towards individualised labour care. BJOG. 2021;128(10):1658–62. https://doi.org/10.1111/1471-­0528.16694. 7. Hodnett ED, Gates S, Hofmeyr GJ, Sakala C. Continuous support for women during childbirth. Cochrane Database Syst Rev. 2013;7:CD003766. https://doi.org/10.1002/14651858. CD003766pub5. 8. Chaillet N, Dumont A. Evidence-based strategies for reducing cesarean section rates: a meta-­ analysis. Birth. 2007;34:53–64. 9. Robson M, Hartigan L, Murphy M.  Methods of achieving and maintaining an appropriate caesarean section rate. Best Pract Res Clin Obstet Gynaecol. 2013;27:297–308. 10. WHO.  Robson classification: implementation manual. Geneva: World Health Organization; 2017. http://apps.who.int/iris. 11. Anderson GM, Lomas J. Determinants of the increasing cesarean birth rate. N Engl J Med. 1984;311:887–92. 12. Knight M, Sullivan EA. Variation in caesarean delivery rates. Specific groups should be monitored at a local level. BMJ. 2010;341:c5255. 13. Betran AP, Vindevoghel N, Souza JP, Gulmezoglu AM, Torloni MR. A systematic review of the Robson classification for caesarean section: what works, doesn’t work and how to improve it. PloS One. 2014;9(6):e97769. https://doi.org/10.1371/journal.pone.0097769. 14. Scarella A, Chamy V, Sepulveda M, Belizan JM. Medical audit using the ten group classification system and its impact on the cesarean section rate. Eur J Obstet Gynecol Reprod Biol. 2011;154:136–40. 15. Homer CS, Kurinczuk JJ, Spark P, Brocklehurst P, Knight M. A novel use of a classification system to audit severe maternal morbidity. Midwifery. 2010;26:532–6. 16. Abha S, Reema C.  A recent way of evaluating cesarean birth. J Obstet Gynecol India. 2009;59:547–51. 17. Moradi F, Aryankhesal A, Heidari M, Soroush A, Rahimi SS. Interventions in reducing caesarean section in the world: a systematic review. Malays J Med Sci. 2019;26(5):21–37. https:// doi.org/10.21315/mjms2019.26.5.3. 18. Bhartua A, Gupta RS, Bhartia S.  Reducing c-section rate in urban hospital serving women attending privately in India—a quality improvement initiative. BMC Pregnancy Childbirth. 2020;20:556. https://doi.org/10.1186/s12884-­020-­03234-­x. 19. Betran AP, Troloni MR, Shang JJ, Gulmezoglu AM. WHO statement on Casearean section rates. BJOG. 2016;123(5):667–70. https://doi.org/10.1111/1471-­0528.13526. 20. World Health Organization. WHO statement on caesarean section rates. Geneva: World Health Organization; 2015. (WHO/RHR/15.02).

Difficult Scenarios in Cesarean Section D. Kiranmai Devineni, Medarametla Vijayshree, Priya Thakur, and S. Shanthakumari

Caesarean section is one of the most performed surgeries on women globally. From being done for most strict indications few decades back, it’s now widely employed for a variety of indications. There is an increase in the incidence ranging from 30 to 80% with wide global variations, and the recommendation from the WHO is 15%. There is a criticism and debate presently on the rates of incidence of caesarean section. Though caesarean delivery has come to be widely used to avoid difficult and traumatic vaginal deliveries, it’s ironic that obstetrician may have to face difficult situations in caesarean delivery. Difficult caesarean birth may result in direct injury to the foetus or asphyxia secondary to delay in delivery of the baby. Difficulty during delivery can also traumatise mother with injury to uterine vessels, cervix, vagina, bladder and excess blood loss. The hospital stay and maternal morbidity increase in difficult caesarean births [1]. Obstetricians need to have experience, knowledge, decision making and technical skill in choosing and executing both instrumental vaginal delivery and difficult caesarean section. To secure the safest and/or quickest route of delivery in the circumstances present at the time, the decision is made, where the anticipated risks to mother and/or baby of an alternative mode of delivery outweigh those of caesarean section [2].

D. K. Devineni (*) Department of Obstetrics and Gynecology, GMC Wanaparty, Hyderabad, Telangana, India M. Vijayshree Department of Obstetrics and Gynaecology, Mamata Medical College, Khammam, Telangana, India P. Thakur Department of Obstetrics and Gynaecology, Mumbai, India S. Shanthakumari Department of Obstetrics and Gynaecology, Hyderabad, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_39

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Difficulties during caesarean section can be classified as 1. Inherent to any surgery and anaesthesia. 2. Inherent to the pre-existing condition as in placenta previa. 3. Pregnancy complications aggravated by caesarean section. 4. Caused by the previous caesarean delivery—dense adhesions placenta accreta (Morbidly adherent placenta). 5. Difficult situations in caesarean section. The key to safe caesarean delivery, optimising the maternal and foetal outcome is anticipation, preparation, acquisition of adequate expertise, able assistance, good technique and technology. The obstetrician should determine the lie, presentation, descent, position and flexion and the second stage disorders like deep transverse arrest, persistent occipito-­ posterior position. In case of breech, the type of breech, the position of the back and the accessibility of feet should be ascertained with the help of ultrasound. The position of placenta should be reconfirmed. In late booking, or referrals in late labour, one should also be aware of the possibility of foetal anomalies like hydrocephalus, foetal ascites, undiagnosed breech and placenta previa. The aim of caesarean delivery should be smooth induction of anaesthesia, quick delivery with minimal trauma to mother and baby.

1 Induction Delivery Interval and Incision Delivery Interval Induction delivery interval of greater than 8 min in general anaesthesia and uterine incision to delivery interval of greater than 3 min are related to higher incidence of neonatal acidosis and low Apgar. In spinal anaesthesia, uterine incision to delivery by more than 3 min is the only factor which influences foetal outcome [3]. Difficulties in delivery in caesarean section may be encountered in 1. Foetus related/presentation related. (a) Deeply engaged head. (b) Floating head. (c) Malpresentations: • Breech, transverse lie, oblique lie, brow, face, occipito-posterior position. (d) Foetal anomalies-hydrocephalus. (e) Conjoint twins. (f) Preterm PROM. 2. Uterus/LUS related. (a) Uterine anomalies.

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(b) Dense adhesions. (c) Uterine leiomyomas. 3. Uterus/Vascular lower segment. (a) Placenta previa. (b) Placenta adherent spectrum. 4. Technical difficulties. (a) Extreme obesity. (b) Failed instrumental delivery. CSFD Caesarean section at full dilatation is a real challenge. The lower uterine segment is stretched vascular and cannot be distinguished from vagina. If care is not taken, the incision might inadvertently open vagina. The presence of deep-down head, lack of liquor, moulding, failed instrumental delivery which further impacts the head and the effects of splinting of foetal spine which prevents flexion of head in already contracted uterus are the factors against expediting the delivery. Use of force to deliver head may cause extension of incision, tears involving cervix, vessels, vagina and sometimes bladder [4].

1.1 Foetus Related/Presentation Related 1.1.1 Deeply Engaged Head This is encountered in late labour or second stage of labour, mostly as deep transverse arrest and persistent occipito-posterior position. Complication rates are higher at 9–10 cm dilatation when compared with 0–1 cm [4]. • Adequate anaesthesia with good relaxation, • Uterine incision at a slightly higher level, • Planning the delivery technique beforehand, and not giving into dilemma and panic. • Nitroglycerin in low doses can be given for relaxation. • Avoid flexing the wrist while delivering head. –– Technique: Push—Abdominal method: Pushing the right hand of the operating surgeon into the space between foetal head and symphysis pubis, and delivering the head by flexion. Abdominovaginal method: The pregnant woman is positioned in a modified lithotomy position, an assistant pushes the head up vaginally till the hand meets the operator’s hand. The hand has to be placed in the form of cup using 3 or 4 fingers to push the head [5].

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1.2 Pull Technique The incision on the uterus is taken at a higher level at the level of shoulders. The higher up incision will help avoid cervix and vagina and facilitate easy delivery of shoulders and arms. It also will help to avoid uterine vessels and prevent colporrhexis and injury to bladder. Patwardhan’s technique: In case of occipito-anterior and transverse positions, the anterior shoulder is delivered out by hooking the arm first. With gentle traction on this shoulder, the posterior shoulder is also delivered out. Hold the trunk of baby gently with both thumbs parallel to spine and with fundal pressure given by assistant the buttocks are delivered followed by legs. The foetal head is the last to be delivered by making an arc and lifting it out of pelvis [6]. Modified Patwardhan’s technique: In occipito-posterior position, the anterior shoulder is delivered out by hooking the arm first followed by delivering the same side leg. This is followed by same side arm, buttocks and trunk of baby. On the opposite side, the other side leg is pulled out gently followed by same side arm and trunk of the baby followed by the head of the baby. Reverse breech technique: The operator places their hand high up in the uterus and reaches the feet and brings them down gently. The delivery of feet is followed by trunk arms and head. An adequate amount of liquor and prior ultrasound to locate the back and feet helps in this technique [7].

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Push techniques take more time and can cause more blood loss, extension of incision, involvement of uterine vessels, cervix and vagina when compared to pull techniques. However, there was not much difference in foetal injuries, in both methods [8]. The risk of endometritis and uterine incision extension and the likelihood of admission to special care nursery (SCN) or neonatal intensive care unit (NICU) was significantly less with reverse breech extraction [1]. The foetal disimpacting system is used as a foetal pillow which when inflated elevates the foetal head. It consists of a base plate 11 cm long and 4.5 cm wide, foldable along the midline of the short axis towards the superior surface, to which a balloon is attached. The balloon is attached to a tube by means of a connector. The tube is in turn connected to a 60 mL syringe. It is preinflated with 40 mL saline and inserted in the vagina at the time of foleys insertion and placed along the anteroposterior axis of pelvis like a vacuum cup. The operator proceeds with caesarean section and just before uterine incision the balloon is further inflated to 120 mL by an assistant, which lifts the foetal head by 3–5  cm facilitating the delivery of the head [9]. Foetal head elevators/spoons are other method. They function as obstetrical ‘shoe horns’ and are available as: the Coyne spoon, the Sellheim spoon and the Murless head elevators. They need less space than the hand and are easier to go around a deeply impacted head. Alternatively, a single blade of an outlet forceps can be used as a spoon to scoop the foetal head out of the pelvis. We do not recommend vacuum in deeply impacted head.

1.3 Comparison of Techniques Used to Deliver a Deeply Impacted Head Beeresh C. S et al. compared the Patwardhan technique versus the Push technique for delivering the foetus [10]. Ninety-eight patients were studied in this retrospective comparison and concluded that the Patwardhan technique was associated with a lower incidence of extension of uterine incision as well as less intraoperative blood loss, uterine artery laceration, less need for blood transfusion, hysterectomy and bladder injury. In study by L Gurney 2020 in BJOG, caesarean at full dilatation had 8.4% incidence of maternal injuries.

1.4 Foetal Morbidity The APGAR scores and the need for NICU admissions did not show a statistically significant difference. There was one still birth in the Patwardhan group and two in Push group. There were no fractures in the Push group, while two babies in the Patwardhan group had a fractured humerus.

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A meta-analysis comparing these techniques used to deliver a deeply impacted foetal head at full dilatation was conducted by Y B Jeve et al. The Push method showed a higher chance of extension of the uterine incision (52%) than the reverse breech extraction method (15%) p   40 weeks there are more chances of failed VBAC.

4 Contraindication of VBAC 1. Classical incision. 2. Obstetrical contraindication. 3. Patient refusal. 4. Breech. 5. Inadequate facilities. 6. 3 or more previous CS. 7. Short inter-delivery period.

5 Criteria for TOLAC: ACOG [4] 5.1 Prior Incision • One prior low transverse incision has decreased the risk. • Classical, inverted T shaped, prior preterm CS delivery, the increased risk (twofold increased risk of uterine rupture). The upper extent of the prior low vertical incision should be known and if it is higher into a contractile portion of the uterus do not attempt TOLAC.  If previous CS was done for a lower segment large myoma, there is a likelihood that it might have been done in the upper segment and if CS was done before 28 weeks, there is a high likelihood of it extending into the upper segment according to a prospective study. Closure: The number of previous CS scars and associated morbidities increases with multiple prior CS. Imaging: Residual myometrial thickness: Minimal thickness between the urinary bladder and amniotic fluid. Jastrow in 2016 [8] measured lower uterine segment thickness between 34 weeks and 39 weeks gestation and divided them into three categories. 1. 4 in 10 min. Misoprostol is C/I. Majority of poor

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outcomes and litigation are prevented if labor is spontaneous and non-augmented and prompt action for abnormal fetal heart tracing should be taken. Third stage of labor: Due to scar, contractility is hampered. So, risk of PPH is present. AMTSL should be routinely done. Early attempt to deliver placenta should be avoided if signs and separation not present. Morbid adherent placenta should be kept in mind if difficulty is present during delivery of placenta. Exploration: Not recommended routinely but should be done in an unexplained uterine bleeding with utmost gentleness. Post natal visits: Contraception is mainstay and delivery interval should be explained. Cost of VBAC vs. Repeat CS: VBAC is cost-effective but its decision should be individualized keeping in mind that fetomaternal complications attributed to VBAC are difficult to handle and costly affair too.

9 Conclusion • Successful vaginal birth has low morbidity, the hospital stay is reduced and recovery is faster. • Timely diagnosis of labor abnormalities is a must to avoid obstructed labor in patients with a uterine scar. • TOLAC in a carefully selected patient yields good results. Risk versus benefit should be the deciding factor. • Obtain medical records specifying the indication of cesarean and the type of uterine incision. • Final decision of TOLAC or elective CS should be of the patient. If the situation changes, the plan can be altered. • Elective CS has its own advantages, it is scheduled, predictable, and avoids frustration with failed TOLAC and risk of rupture but future risks of CS should also be taken into account.

References 1. https://www.who.int/news/item/16-­06-­2021-­caesarean-­section-­rates-­continue-­to-­rise-­amid-­ growing-­inequalities-­in-­access. 2. MacDorman MF, Menacker F, Declercq E.  Cesarean birth in the United States: epidemiology, trends, and outcomes. Clin Perinatol. 2008;35(2):293–307. https://doi.org/10.1016/j. clp.2008.03.007. 3. Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, et al. Maternal morbidity associated with multiple repeat cesarean deliveries. National institute of child health and human development maternal-fetal medicine units network. Obstet Gynecol. 2006;107:1226–32. 4. American College of Obstetricians and Gynecologists: vaginal birth after cesarean delivery. Practice Bulletin No. 184. 2017. 5. Vachon-Marceau C, Demers S, Bujold E, Roberge S, Gauthier RJ, Pasquier JC, Girard M, Chaillet N, Boulvain M, Jastrow N.  Single versus double-layer uterine closure at cesar-

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ean: impact on lower uterine segment thickness at next pregnancy. Am J Obstet Gynecol. 2017;217(1):65–e1. 6. Trojano G, Damiani GR, Olivieri C, Villa M, Malvasi A, Alfonso R, Loverro M, Cicinelli E. VBAC: antenatal predictors of success. Acta Biomed. 2019;90(3):300. 7. Royal College of Obstetricians and Gynaecologists. Birth after previous caesarean birth. Green-­top guideline no. 45. 2015. 8. Jastrow N, Demers S, Chaillet N, et  al. Lower uterine segment thickness toprevent uterine rupture and adverse perinatal outcomes: a multicenter prospective study. Am J Obstet Gynecol. 2016;215(5):604.e1. 9. American College of Obstetricians and Gynecologists. ACOG practice bulletin no. 205: Vaginal birth after cesarean delivery. Obstet Gynecol. 2019;133(2):e110. 10. Ritchie EH. Pregnancy after rupture of the pregnant uterus: a report of 36 pregnancies and a study of cases reported since 1 932. J Obstet Gynaecol Br Commonw. 1971;78:642. 11. Cunningham FG, Leveno KJ, Bloom SL, Dashe JS, Hoffman BL, Casey BM, Spong CY.  Williams obstetrics. New  York, NY: McGraw- Hill Companies Inc; 2018. ISBN 978–1–259-64432-0; MHID 1–259–64432-4. 12. Hibbard JU, Gilbert S, Landon MB, et al. Trial of labor or repeat cesarean delivery in women with morbid obesity and previous cesarean delivery. Obstet Gynecol. 2006;108:125.

Caesarean Myomectomy Anuja Bhalerao, Savita Somalwar, Krutika Bhalerao, and Shaily Agarwal

1 Introduction One of the most controversial issues in the field of obstetrics and gynaecology is the presence of known or incidental leiomyomas during pregnancy and management of pregnancy with myoma. Between 0.5 and 5% of pregnant women are affected with myomas [1]. They are usually asymptomatic, but there are more possibilities of miscarriage, preterm labour pains, premature rupture of membranes, antepartum haemorrhage, abruptio placenta, malpresentations and caesarean sections. Total 10–30% of the pregnancies develop some complications related to leiomyomas [2]. They may have red degeneration or torsion, especially during the second trimester of pregnancy. Size, quantity and location of myoma all have an effect on the outcome of a pregnancy. Obstructed labour, cervical dystocia or complications during a caesarean section (CS) are all possible symptoms. It can also induce uterine subinvolution, postpartum endometritis and postpartum haemorrhage [3, 4]. Getting access to the foetus in patients with the lower uterine region fibroids, and removing fibroids after a caesarean section in order to close the uterine incision are the main reasons to remove uterine fibroids during caesarean section [5].

A. Bhalerao (*) NKP Salve Institute of Medical Sciences and Lata Mangeshkar Hospital, Nagpur, India S. Somalwar NKP Salve Institute of Medical Sciences, Nagpur, India K. Bhalerao Department of Obstetrics and Gynaecology, Wardha, India S. Agarwal GSVM Medical College, Kanpur, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_41

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Myomectomy during caesarean section has not been done routinely due to risk of significant bleeding, which results in increased postoperative morbidity. However, with judicious patient selection, anaesthesia advancements, adequate blood availability, devascularisation methods and considering multiple disciplines, obstetricians are now confident and comfortable doing myomectomy with caesarean section, preventing morbidity due to repeated surgeries, anaesthetic complications and extra expenditure [6].

2 Indications and Contraindications to Perform Caesarean Myomectomy Currently, there are no standard or established guidelines for the indications and contraindications of caesarean myomectomy (Tables 1 and 2). The patient should be educated, and the choice to perform a myomectomy should be individualised only on the basis of patient’s safety. Myomectomy should be avoided if the placenta is attached below the fibroid base due to the danger of uncontrolled bleeding. Every effort should be made to keep blood loss to a minimum. The fibroid’s connection to placental attachment should be understood; if the placenta is connected below the fibroid base, myomectomy should be avoided due to the risk of uncontrolled bleeding. Surgery might take longer and result in significant blood loss. In their large study, Song et al. discovered that patients who had myomectomy at CS had lower haemoglobin levels and required more time than controls. However, the decrease and additional time required were negligible. Park and Kim [7–9] discovered similar results. Myomectomy is not contraindicated during CS, as previously supposed. If the procedure appears to be safe, it should be done on a case-by-case basis. Table 1 Indications for caesarean myomectomy

• Myoma more than 5 cm in size • Myomas situated anteriorly and lower segment myomas • Myomas with pedunculations • Myomas that degenerate • Intractable pain caused by pedunculated subserosal fibroid twisting; red degeneration refractory to conservative therapy; or enormously enlarged myoma giving abdominal discomfort to the patient

Table 2  Contraindications for caesarean myomectomy

• Age > 40 years • Multiple myomas • Cornual placed myomas • Posteriorly positioned myomas • Asymptomatic myomas • Bleeding tendency • Previous history of uterine rupture

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3 Surgical Techniques of Caesarean Myomectomy There are two methods for removing leiomyomas after a caesarean section [6]: 1. Endometrial myomectomy 2. Serosal myomectomy (unusual method) Both treatments employ the same intracapsular myoma removal concept, with the only difference being the route of myoma removal. Endometrial myomectomy offers certain advantages over serosal myomectomy

Serosal myomectomy is the removal of leiomyomas by incisions on the uterine surface, comparable to abdominal or laparoscopic myomectomy. The main difference is that the uterus is larger and more vascularised after a caesarean section. Uterine involution compresses the large veins in the endometrial cavity while leaving the surface blood supply alone, increasing the risk of post-­ serosal myomectomy haemorrhage. In a recent study, a large 14 cm myoma that was causing severe agony to the patient was successfully removed during the first trimester at 11 weeks. The patient brought her pregnancy to term and had a healthy child. Bhatla et al. performed another straightforward myomectomy in the second trimester with no negative pregnancy outcomes [6, 10]. In the present day, myomectomy during caesarean delivery is still debatable. Endometrial myomectomy, a novel caesarean myomectomy approach, was developed by Cengiz Tokgöz, MD, in 2013. The primary goal of this innovative approach is to reduce uterine scarring and adhesion development [11]. The uterus is exteriorised from the abdominal cavity after the baby and placenta have been removed. The uterine cavity is cleaned with gauze, and any bleeding from the uterine incision is stopped. The uterine surface and cavities are extensively examined for leiomyomas, and their anatomical positions and sizes are determined immediately. Key Points • The leiomyomas located around the lower uterine incision site are excised from the subendometrial–intramyometrial region. In such cases, no additional suturing is required since the dead space is closed together with the suturing of the low uterine incision line. • Following palpation and localisation, leiomyomas are transferred from the serosal to the endometrial sites, and an endometrial–transmyometrial incision is created with a scalpel or electrocautery knife to access the leiomyoma. The leiomyoma is excised without its capsule utilising blunt and sharp dissections. Any vascular structures around the root of the myoma are clamped and sutured. • If multiple leiomyomas are present and they are not located in close proximity, then all leiomyomas are removed one by one and endometrium is incised for each leiomyoma. The endometrium has the unique quality to involute rapidly and the endometrial incisions become smaller in size, which makes the ­endometrial scar smaller than the original incision. For non-bleeding smaller endometrial incisions ( grade 2 not controlled on antibiotics) Elective indications are: Invasive carcinoma cervix PAS diagnosed antenatally

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Prerequisites Counselling of the patient and relatives should be done in women with high risk factors It is necessary to obtain proper consent A sufficient supply of blood should be made available Antibiotics are to be provided as a preventative measure In difficult instances like placenta accreta syndrome, a multidisciplinary team involving obstetricians, anaesthesiologists, urosurgeons, vascular surgeons and interventional radiologists should be accessible When a hysterectomy is chosen, the operating room and trolley should be prepared with two sets of hysterectomy clamps, a mixtard on the cart, a senior experienced anaesthetist and nursing staff

In anticipation of variations before having a hysterectomy, it is critical to think about a few issues [7]. Clots can impair normal pelvic architecture, as in the case of big broad ligament haematomas. Pedicles should be fixed twice in the correct anatomical plane to minimise ligature slippage since they are more vascular, oedematous and bulkier. The possibility of adherent bladder in women with a previous caesarean should be evaluated, and if the adhesion is significant, we may need to access the bladder and get the appropriate plane for dissection. Uterine angle expansions increase the danger of ureteric injuries; the bladder should be pushed down far enough by sharp dissection to enable the ureters to fall laterally, lowering the possibility of injury. If hysterectomy is done after caesarean section (CS) at full dilatation, one has to be careful while doing total hysterectomy as the cervix may be difficult to identify. One has to be gentle with the pedicles as tissues are friable; hence follow the adage ‘go near the pedicle rather than pulling it’. • When a hysterectomy is performed following a vaginal birth, it is done using normal operating techniques. • In emergency conditions, when internal ileac artery ligation is necessary, enough exposure with either a midline vertical or a pfannensteil incision is required. • Once inside, a self-retaining retractor and cephalad traction on the uterus are the best ways to get exposure. • The placenta is normally removed after caesarean section, except in placenta accreta syndrome when the placenta is left untouched. In some situations, a hysterectomy is already in the works. • In the context of a probable adherent placenta, national guidelines in the United Kingdom [8] indicate that accessing the uterus at a location away from the placenta and delivering the infant without disturbing the placenta be explored.

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• Surgical Steps: Bilateral round ligaments are divided and ligated twice near the uterus using Kocher clamps To avoid injury to Sampson’s artery, the clamp tips should be placed in the avascular portion of the broad ligament Opening of Broad Ligament The anterior peritoneal fold of broad ligament is opened downwards up to uterovesical fold of peritoneum. Posteriorly, it is extended laterally and parallel to the infundibulopelvic ligament to expose the retroperitoneum. This allows visualisation of anatomy of ureter and retroperitoneal space A window is made in the posterior fold of peritoneum of broad ligament for application of clamps close to uterus and clamping fallopian tube, utero-ovarian ligament and ovarian vessels. These pedicles are doubly ligated and the posterior leaf is dissected towards uterosacrals too Dissection of the Bladder The bladder must be dissected and pushed down before the uterine artery clamps are applied. Sharp dissection of the bladder is recommended since most women have had prior surgery. To avoid extremely vascular bladder pillars laterally, it is critical to stay near the centre Many surgical techniques to the treatment of PAS have been proposed over time, with varying results. One involves separating the bladder up to the cervico-vaginal junction prior to uterine incision, in order to ligate and separate the aberrant blood veins that run between the uterus and the bladder Uterine clamps must be used with caution to avoid harm to the ureter, which runs beneath the uterine arteries. To avoid harm to the ureters, the aid might apply traction in the opposite direction from where the uterine veins are constricted. At the level of the internal cervical os, a Heaney clamp is inserted with the distal part perpendicular to the vasculature. Blood loss will be significantly reduced if bilateral uterine are clamped, sliced and doubly fixated; it should be noted that the uterine are skeletonised Back-bleeding from the uterus is reduced by using a second clamp on the specimen side, which might restrict the operational field For pedicles, a 1-0 or 2-0 polyglycolic suture with a Heaney stitch is used; some people recommend slipping a suture past the clamp’s tip and tying behind the clamp Heaney stitch halves the pedicle and decreases the chances of vessels retracting Clamps placed carefully medially, sliding along the parametrial tissue and close to the cervix, allow ligation of branches of the uterine artery not ligated with the initial clamp and assure the ureter’s safety With the uterus’s full blood supply now secured, a key decision must be taken regarding an urgent caesarean hysterectomy [9–14]

3 Total or Partial Hysterectomy In an unstable woman or one with considerable amount of bleeding, the surgeon has to decide performing a partial hysterectomy, which reduces surgical time achieving the main aim of haemostasis. Although a subtotal hysterectomy can save a woman’s life, it entails cutting the uterus with a scalpel above the ligated uterine arteries and angling the scalpel blade medially and downwards. The cervix is removed as an inverted cone, which aids in the approximation of the cervical stump’s borders regardless of dilatation.

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The cervical stump can be approached anterior to posterior while avoiding the bladder using interrupted figure-of-eight ligatures. If the patient’s health is good, the cervix can be removed. The cardinal ligament has been clamped, severed and fixed using the cut medially and tie laterally principle. Metzenbaum scissors are used for sharp bladder dissection. Bladder dissection should never extend more than 1 cm beyond the current cardinal ligament dissection. The next step is to locate the dissection’s lowest point: the cervix–vaginal junction. This juncture is generally felt between the thumb and forefinger by palpating the higher vaginal walls and coming into contact with the thickened cervix. When the cervix is dilated, the best strategy is to roll each clamp of the cardinal ligament complex off the cervix so that it is perfectly aligned with the lateral cervical wall. This allows the surgeon to move along the cervix as each pedicle collapses laterally, protecting the ureter. In some cases, the uterosacral ligaments can be seen and may need to be individually clamped to be completely ligated. The vagina is opened when the dissection of the cardinal ligaments reaches the lower limit of the cervix. The cervix is amputated using curved scissors. To finish the dissection under direct vision, position the inside blade of the scissors slightly under the cervix in the vaginal fornix and circumscribe the upper vagina. Allis or Kocher clamps apply traction to the anterior, posterior and lateral angles of the vaginal wall. The vaginal epithelium is extremely delicate and must be handled with caution.

4 Vault Closure Closure of the vaginal cuff begins with supporting angle sutures that incorporate the lateral vaginal angles, lower cardinal ligament pedicles and uterosacral pedicles, either with continuous or interrupted sutures, or by leaving the cuff open and securing haemostasis of the anterior and posterior cuff edges with a continuous non-­ locking suture. If the surgeon suspects bladder damage at any time during the procedure, the bladder may be filled with a methylene blue solution and the operative field checked for dye extravasation. If an unintentional cystotomy has occurred, the region is dissected to allow for the placement of two rows of sutures without strain. To seal the bladder, two continuous layers of 4.0 polyglycolic sutures are used, with the second layer imbricating the first. Never use permanent suture material to close a bladder. The bladder is then refilled to maintain its integrity. When bladder repair is necessary, postoperative antibiotics and Foley catheter drainage are provided for 7–14 days. Sponges and retractors are removed, and instrument, needle and sponge counts are checked. The abdominal incision is closed in the routine fashion.

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In unstable patients, the technique that is used is clamp/cut/drop. Once the uterus is out, all the pedicles are doubly transfixed and haemostasis is ascertained.

5 Advantages/Disadvantages: Subtotal/ Total hysterectomy • Total hysterectomy is the surgery of choice in cases of central placenta previa. • If the patient is unstable, removing the cervix is not necessary for haemostasis, or if the bleeding is caused by uterine atony, the procedure is subtotal. • Subtotal hysterectomy has the following advantages: shorter operating room time, less hospital time and a lower risk of bladder/ureteral injuries. The risks of cancer in the cervical stump, the need for frequent cytology and bleeding or discharge from the remnant cervical stump are all disadvantages of subtotal hysterectomy [15–25].

6 Salpingo-Oophorectomy Because of the size of the adnexal vessels and their proximity to the uterus, one or both adnexa may need to be removed for haemostasis. In this case, preoperative counselling should also be provided. Complications Maternal morbidity ranged between 26.5 and 31.5% [1–5, 7–16, 20–23, 26]. Blood transfusion (88%) was the most common consequence, followed by fever episodes (26.5%), neonatal mortality (22.8%), bladder injuries (8.8%), wound infection, dessiminated intravascular coagulation (DIC), ileus, vaginal cuff haemorrhage and adnexectomy. Maternal mortality varied from 0 to 12.5%, with a mean of 4.8% [1–5, 15–26] Urinary Tract or Bowel Injuries Overall, 2/1000 women undergoing caesarean hysterectomy have bladder laceration, 0.3/1000 have ureteral injuries and 1/1000 have bowel injury Cystotomy bladder laceration is most commonly caused by blunt or sharp dissection during vesicouterine space dissection for the development of a bladder flap, and it is most common when the bladder is adherent, as in cases with prior scar or progressed bladder, as in second-­ stage caesareans A gush of fluid and the visualisation of Foley’s bulb are used intraoperatively to diagnose bladder damage When a bladder injury occurs, the bladder is separated, a hysterectomy is performed, the ureters are examined and the bladder is later sutured with 2-0 or 3-0 delayed absorbable suture material in two or three layers, the first being the bladder mucosa and the second muscle layer, which is sutured with interrupted sutures; the catheter is kept in place for 7–14 days, depending on the severity of the damage Ureteral Disease Ureteric injuries are most common following hysterotomy extensions into the broad ligament In such cases, a methylene blue test is performed, and dye extravasation in the pelvis is evaluated

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For proximal lesions, urologist-assisted care may include ureteric catheterisation, ureteroneocystostomy, ureteroureterostomy, psoas hitch and Boari flap formation Bowel Complications Weak spots in the small bowel are serosal rips They can be sewn with fine absorbable or non-absorbable sutures

Postoperative Care • Fluids injected intravenously—about 2000 mL of intravenous fluids and packed red cells should be administered to combat blood loss of 1000–1500 ccs • The patient must be kept under observation in the high dependancy unit (HDU) • Analgesia— placenta accreta spectrum (PAS) is a popular and effective method of analgesia • Vital signs should be monitored • If a bladder is injured, the catheter is kept for 24 h or 14 days • Bowel care—as soon as bowel motility improves, oral medications can be started • Early ambulation is advised, and low-dose heparin can be given prophylactically for thromboprophylaxis if necessary

7 Important Points to Remember • No risk assessment system can predict every situation in which a caesarean delivery will be required. • Preoperative risk factors include a history of CS, placenta previa and accreta. • The presence of preoperative risk factors should facilitate consultation, referral or transfer of patients to a tertiary care facility before surgery. Because of the complexities of the surgery and decision-making, it is preferable to involve an experienced obstetrician at an early stage. • The most important factors are optimal preoperative preparation, a multidisciplinary approach and minimising intraoperative blood loss. The incidence of rupture of the previously scarred uterus with placenta accreta or placenta previa with accreta is increasing, as is the number of caesarean sections performed in the last decade. • Caesarean hysterectomy is required for these women. All doctors who treat pregnant women must be prepared to treat these problems and, if necessary, perform caesarean hysterectomy. Caesarean hysterectomy is a rare procedure in obstetric practise. When the occasion arises, it frequently takes place in harsh conditions. • Caesarean hysterectomy is one of the most difficult obstetric procedures when performed as an emergency treatment. Some experience with simple, unhurried, preplanned caesarean hysterectomy is beneficial in the educational development of obstetrics and gynaecology professionals so that they can perform this surgery successfully in difficult emergency situations.

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References 1. Christopoulos P, Hassiakos D, Tsitoura A, Panoulis K, Papadias K, Vitoratos N. Obstetric hysterectomy. A review of cases over 16 years. J Obstet Gynecol. 2011;31(2):139–41. 2. Kwee A, Boto ML, Visser GH, Bruinse HW. Emergency peripartum hysterectomy: a prospective study in The Netherlands. Eur J Obstet Gynecol Reprod Biol. 2006;124(2):187–92. 3. Karayalcin K, Ozcan S, Ozyer S, Mollamahmutoglu L, Danisman N. Emergency peripartum hysterectomy. Arch Gynecol Obstet. 2010;283(4):723–7. 4. El Jallad MF, Zayed F, Al-Rimawi HS.  Emergency peripartum hysterectomy in northern Jordon: indications and obstetric outcome (an 8 year review). Arch Gynecol Obstet. 2004;270(4):271–3. 5. Yamani Zamzami TY. Indications of emergency peripartum hysterectomy: review of 17 cases. Arch Gynecol Obstet. 2003;268(3):131–5. 6. Plauche Plauché WC, Wycheck JS, Iannessa M, et al. Cesarean hysterectomy on LSU Service of Charity Hospital. South Med J. 1983;76:1261. 7. Seago DP, Roberts WE, Johnson VK, et al. Can scheduled cesarean hysterectomies be justified? Am J Obstet Gynecol. 1999;180:1385. 8. RCOG Green-top Guideline Number 27. Placenta praevia, placenta accreta and vasa praevi diagnosis and management. London: RCOG Press; 2011. 9. RCOG Green-Top Guideline 52. Postpartum haemorrhage, prevention and management. London: RCOG Press; 2009. 10. Knight M, et  al. Cesarean delivery and peripartum hysterectomy. Obstet Gynecol. 2008;111:409–12. 11. Shellhaas C, et al. The frequency and complication rates of hysterectomy accompanying cesarean delivery. Obstet Gynecol. 2009;114:224–9. 12. RCOG. Confidential enquires into maternal and child health. Saving mothers lives. London: RCOG Press; 2007. 13. Rossi AC, et al. Emergency postpartum hysterectomy for uncontrolled postpartum bleeding. A systematic review. Obstet Gynecol. 2010;115(3):637–44. 14. Flood KM, Said S, Geary M, et  al. Changing trends in peripartum hysterectomy over four decades. Am J Obstet Gynecol. 2009;200:632e1–6. 15. Engelsen IB, Albrechtsen S, Iversen OE. Peripartum hysterectomy—incidence and maternal morbidity. Acta Obstet Gynecol Scand. 2001;80(5):409–12. 16. Langdana M, Geary W, Haw D, Keane F. Peripartum hysterectomy in the 1990s: any new lessons? J Obstet Gynecol. 2001;21:121–3. 17. Sheiner E, Levy A, Katz M, Mazor M. Identifying risk factor for peripartum cesarean hysterectomy. A population based study. J Reprod Med. 2003;48(8):622–6. 18. Kastner ES, Figueroa R, Garry D, Maulik D. Emergency peripartum: experience at a community teaching hospital. Obstet Gynecol. 2002;99:971–5. 19. Bakshi S, Meyer BA. Indications for and outcome of emergency peripartum hysterectomy. A five year review. J Reprod Med. 2000;45(9):733–7. 20. Zelop CM, Harlow BL, Frigoletto FD, Safon LE, Saltzman DH. Emergency peripartum hysterectomy. Am J Obstet Gynecol. 1993;168:1443–8. 21. Stanco LM, Schrimmer DB, Paul RH, Mishell DR. Emergency peripartum hysterectomy and associated risk factors. Am J Obstet Gynecol. 1993;168(3):879–83. 22. Clark SL, Yeh SY, Phelon JP, Bruce S, Paul RH. Emergency hysterectomy for obstetric haemorrhage. Obstet Gynecol. 1984;64(3):376–80. 23. Miller DA, Chollet JA, Goodwin TM. Clinical risk factors for placenta previa-placenta accreta. Am J Obstet Gynecol. 1997;177(1):210–4. 24. Chestnut DH, Eden RD, Gall SA, Parker RT. Peripartum hysterectomy: a review of cesarean and post partum hysterectomy. Obstet Gynecol. 1985;65(3):365–70. 25. O’Leary JA. Uterine artery ligation in the control of postcesarean haemorrhage. J Reprod Med. 1995;40(3):189–93. 26. Porro E.  Dell'amputazionne utero-ovarica comecomplemento di tagliocesareo. Ann Univers Med Chir. 237:289, 18767.

Part XI Management of Labour

Induction of Labour Dalia Rafat and Farah Azhar

1 Introduction Uterine contractions in pregnant women can either start spontaneously or be induced artificially. Factors influencing onset and progress of labour in pregnant women are complex, controversial and not uniform in all women in all clinical settings. Artificial stimulation of uterine contractions to accomplish delivery prior to the onset of spontaneous contractions is referred to as induction of labour (IOL). Induction of labour may become necessary when a medical indication for birth occurs before labour begins spontaneously. This indication may be related to the maternal and/or foetal condition. It is typically recommended when allowing the pregnancy to continue is believed to be at least as risky for the mother and/or foetus as delivery. Morbidity and mortality in infants is more in late preterm and early term babies than those born after 39 completed weeks. Rarely, labour can also be induced for convenience of the woman or the prenatal healthcare provider. Over the past few decades, the incidence of induction of labour has continued to rise. In most developed countries, around one in four infants is delivered at term following this procedure. The rates in low- and middle-income countries are usually lower, but they can be as high as those in high-income countries in specific circumstances.

D. Rafat (*) · F. Azhar Department of Obstetrics and Gynaecology, Jawaharlal Nehru Medical College, AMU, Aligarh, UP, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 R. Garg (ed.), Labour and Delivery, https://doi.org/10.1007/978-981-19-6145-8_43

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2 Indications and Contraindications of Induction of Labour The relative risk of carrying the pregnancy to term versus delivering it is mostly impacted by gestational age and the severity of the maternal/foetal disease, and it is difficult to predict with precision. Indications can be divided into two categories: medical and non-medical.

2.1 Medical Indications Induction of labour is a viable therapeutic option when benefits of expeditious delivery outweigh the hazards of prolonging a pregnancy for mother and/or foetus. Following are few obstetric, maternal and foetal conditions that constitute medical indications of labour induction [1–6]. These are not absolute indications and obstetrician should examine maternal and foetal conditions, gestational age, cervix state and other criteria when considering induction of labour.

2.1.1 Obstetric Conditions • Postdates >41 weeks • Postterm pregnancy >42 weeks • Prelabour rupture of membranes • Oligohydramnios • Chorioamnionitis • Abruptio placentae • Gestation hypertension, preeclampsia, eclampsia and hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome • Intrahepatic cholestasis of pregnancy • Gestation diabetes mellitus 2.1.2 Maternal Conditions • Diabetes mellitus • Chronic hypertension • Renal disease • Chronic pulmonary diseases 2.1.3 Foetal Conditions • Foetal growth restriction • Isoimmunisation • Multiple gestation • Intrauterine foetal demise (IUFD) and history of IUFD in previous pregnancy Sometimes due to logistic problems like increased distance from the hospital and history of rapid labour, IOL may be done.

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2.2 Non-Medical Indications/Elective Induction Induction of labour when there is no medical evidence that the benefits of delivery clearly outweigh the risks is typically termed as ‘elective’. Various recommending agencies like the American College of Obstetricians and Gynecologists (ACOG) [1] and the Society of Maternal-Fetal Medicine (SMFM) have concluded that offering low-risk nulliparous women an elective induction of labour (IOL) at 39 weeks of pregnancy (in a well-dated pregnancy) is a reasonable option that should be discussed with these women and their obstetricians, taking into account available resources. Furthermore, correct determination of gestational age is critical. The guidelines advise against elective induction before 39 + 0 weeks of gestation and in suboptimally dated pregnancies. Based on several observational studies and randomised trials, elective induction at 39 weeks is found to have a number of potential benefits like: • • • •

Reduced stillbirths. Decreased caesarean births. Decrease in incidence and consequences of large for gestational age babies. The capability to adjust the time of delivery when this is crucial (e.g. women with a history of rapid labour or who live far from the hospital and thus risk of out-of-hospital delivery). Boulvain (2015) [7] assigned macrosomic mothers to IOL versus expectant management and found the risk of shoulder dystocia was reduced and caesarean delivery rate was not increased, nor brachial plexus injury or neonatal morbidity.

3 Contraindications of Induction of Labour Contraindications of induction of labour are generally the conditions that preclude spontaneous labour and vaginal birth. These can be absolute and relative contraindications. Following are obstetric, maternal and foetal conditions in which the risk of induction of labour and resulting vaginal delivery outweighs the risks associated with caesarean delivery.

3.1 Contraindications 3.1.1 Obstetric Conditions • Cephalopelvic disproportion • Major placenta previa • Placenta accreta spectrum • Umbilical cord prolapse • Previous classical caesarean section (CS)

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• Previous uterine rupture • Previous myomectomy entering the endometrial cavity • Two or more previous low-transverse caesarean sections

3.1.2 Maternal Conditions • Active primary genital herpes • Invasive cervical cancer 3.1.3 Foetal Conditions • Transverse foetal lie • Breech presentation • Triplet or higher-order pregnancy • Category III foetal heart rate (FHR) tracing • Stages 2–4 foetal growth restriction

4 Preparations for Induction of Labour To achieve a successful labour induction, both the patient and the care giver must be well prepared prior to starting the procedure. Care giver should have performed a thorough evaluation of maternal and foetal condition to ensure that the indication and timing are appropriate and that there are no contraindications to labour or vaginal birth [8]. Prior to labour induction, informed consent should be taken from the women. A woman’s individual needs and preferences should always be taken into account and they must have the opportunity to make informed decisions in partnership with their healthcare professionals. The process of informed consent should take place at the proper literacy level and in a language that the lady understands. The information imparted should include induction indications and alternatives, planned medicines and procedures, including side effects and problems, the likelihood of caesarean delivery as well as doing nothing at all. Discussion regarding the labour and birth process should ideally begin during the antenatal period, with time for questions and responses. Preferably by the time a pregnant woman gets admitted to the hospital for labour induction, she should be fully informed about the risks, benefits and alternatives and have a thorough discussion with her maternity care provider with all of her questions and concerns addressed. Aside from the above essential aspects, other patient preparation and laboratory testing are the same as for women in spontaneous labour.

5 Assessment of Success of Labour Induction The success of labour induction depends on cervical and non-cervical factors [8, 9].

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5.1 Cervical Factors A favourable cervix is linked to a shorter induction delivery interval and higher chances of vaginal birth. Women with unfavourable cervixes have lesser chances of successful induction but still are at an increased risk of caesarean delivery with expectant management. The a randomized trial of induction versus expectant management (ARRIVE) trial enrolled 6106 women and randomised them to elective induction versus expectant management and found that caesarean rates improved regardless of cervical status, so labour induction should not be avoided even in women with an unfavourable cervix. It concluded that elective induction at 39 weeks decreases caesarean and maternal and perinatal risks. Different scoring systems exist to predict labour outcome like the Bishop score, Fields system and Burnett, Caldor and Friedman variants of the Bishop system. The Bishop score is the most widely utilised method in clinical practice. Despite its limitations, it appears to be the best available tool for assessing cervical status, and it is as good as, if not better than, foetal fibronectin or sonographic cervical length measurement in terms of predicting successful induction. The Bishop score is determined by the presenting part’s station as well as four cervix characteristics: dilatation, effacement, consistency, and position. A score of 2 is given to each component to form a cumulative score of 10. Lower Bishop scores have been linked to a higher likelihood of caesarean birth, whereas higher Bishop scores have been linked to a higher chance of vaginal delivery. Score 0 1 2 3

Dilatation (cm) Closed 1−2 3–4 5–6

Position of cervix Posterior Mid position Anterior –

Effacement (%) 0−30 40–50 60–70 80

Station (−3 to +3) –3 –2 −1, 0 +1, +2

Cervical consistency Firm Medium Soft –

Although there is no widely accepted cut-off of Bishop score for determining favourability, most obstetricians consider a score of ≥6 as favourable and a score ≤3 as unfavourable; scores of 4 or 5 are in the grey zone. If the cervix is unfavourable, a ripening technique is usually used prior to induction to reduce the induction time and increase the chances of a vaginal delivery. Mechanical interventions such as the insertion of balloon catheters and pharmacologic medicines, such as prostaglandins (PGs), are the two main approaches for cervical ripening. Conversely, if the cervix is found to be favourable, induction is initiated without cervical ripening.

5.2 Non-Cervical Factors Factors besides cervical status, which are linked to poorer chances of successful induction and higher likelihood of caesarean birth, are:

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• Higher body mass index • Nulliparity • Gestational age (success of late preterm [34–36 weeks] is same as term): success of IOL increases with gestational age • Mother’s age • Intact membranes • Short stature • Macrosomia

6 Techniques of Cervical Ripening and Induction of Labour Ripening of cervix can be done in outpatient or inpatient setting. The ideal agent or method for cervical ripening and induction of labour should be simple to administer, non-invasive, effective in a timely manner and should not increase maternal, foetal or new-born morbidity.

6.1 Outpatient Induction In a Cochrane review (2020) by Alfirevic, no differences in outcome were found in outpatient versus inpatient induction but outpatient methods must act slowly, so options include dinoprost insert, Foley catheter and low-dose misoprost. Although the ideal agent/method has not yet been identified, the two major techniques employed for the purpose are: 1. Mechanical techniques 2. Pharmacologic techniques

6.1.1 Mechanical Techniques Mechanical methods were the first methods developed to ripen the cervix and induce labour [8, 9]. During recent decades they have been largely substituted by pharmacological methods. Mechanical techniques include: 1. Transcervical balloon catheters 2. Hygroscopic dilators 3. Extra-amniotic saline infusion 4. Amniotomy 5. Membrane stripping Mechanism of action: Mechanical methods act by direct physical pressure on the internal cervical os and by causing the release of prostaglandins from the decidua, adjacent membranes and/or cervix. These effects combine to promote a

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number of biochemical and biophysical changes that lead to cervical ripening and an increase in myometrial contractility. Contraindications: There are no absolute contraindications for the use of mechanical methods if the candidate is suitable for vaginal delivery. However, relative contraindications can be there depending upon the clinical scenario, such as low-lying placenta (risk of haemorrhage), ruptured membranes (risk of chorioamnionitis) or polyhydramnios. Side effects: Mechanical methods are relatively safe. Except for small discomfort, there are no associated systemic side effects and no increased risk of maternal and neonatal infectious morbidity has been observed. There is lesser risk of tachysystole compared to pharmacologic methods. Transcervical Balloon Catheters Overview: A catheter is introduced through the cervix into the extra-amniotic space followed by balloon insufflation. They work by applying local pressure on the cervix leading to release of local prostaglandins. There are two types of balloon catheters that can be used for this purpose: (a) Single balloon (16–18 F, less expensive, readily available) (b) Double balloon (specifically designed for cervical ripening, commercially available) No clinically significant differences in clinical outcomes have been seen among double- versus single-balloon catheters. Procedure: A deflated catheter is inserted in the extra-amniotic space under aseptic condition. It is then inflated with either large (60–80 mL) or small (30 mL) volume of saline. The inflated balloon is then retracted to rest against internal os. Few clinicians practice taping of the catheter’s end to the inner thigh, tensioning it and readjusting it to maintain tension at regular intervals. Some others put a weight to the catheter’s end and suspend it from the bed’s end. Most of the randomised trials done till now have reported that tensioning or weighted traction may reduce the time of spontaneous balloon ejection but does not reduce the time to delivery. Balloon catheter is usually left for 12 h or if it is expelled on its own upon cervical dilatation. Although there is no absolute contraindication to leaving it in place for more than 12 h, studies have found that removing non-extruded catheters after 12 h and starting oxytocin infusion resulted in significantly more vaginal deliveries than waiting 24 h before removal. Oxytocin and amniotomy is usually performed after balloon removal/extrusion but pharmacologic methods can be used concurrently with balloon catheters as they increase the delivery rates and reduce the induction delivery interval. Studies have found no increased adverse obstetric or perinatal outcomes; instead, reasonable benefits are noted over the use of a single method alone. When concurrent administration is planned, both a fixed low dose of pharmacologic agent and standard incremental dose regimen are acceptable options. Advantages include that these can be

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applied in women with previous caesarean section where misoprostol is contraindicated and in patients with growth-restricted foetus or oligohydramnios as here there are concerns about intrapartum foetal heart rate abnormalities associated with uterine tachysystole in early labour. But in women with ruptured membranes balloon devices can cause chorioamnionitis, so cervical ripening agents should be preferred. Continuous foetal heart rate monitoring should be done when women with intrauterine growth restriction are undergoing induction as these are chronically hypoxiated. Low-lying placenta is an absolute contraindication; lower genital tract infection is another contraindication. Compared to prostaglandins, Foley catheter causes less tachysystole. They do not increase the risk of preterm birth in future pregnancies nor the rate of infection. Chances of vaginal birth were more in misoprost group versus Foley catheter group [10, 11]. In a Cochrane review [12] by dee Van on more than 8000 women, no cases of uterine scan dehiscence or rupture by balloon catheter were found in women with previous caesarean. So, mechanical methods are a safer alternative versus prostaglandins (as they have 1.2% rate of rupture). Hygroscopic/Osmotic Dilators Hygroscopic dilators are introduced into the cervical canal and allowed to absorb moisture from cervical tissue and expand. They are as safe and effective as other cervical ripening agents but are more commonly used during pregnancy termination than for induction or ripening. They are of two types: (a) Natural (laminaria tent) (b) Synthetic (dilapan-S; expensive but act more quickly) Natural osmotic dilators are normally removed 12–24 h after insertion, although synthetic ones can be removed as soon as 6–8 h following placement. Amniotomy Amniotomy involves artificial rupture of membranes (ARMs) by perforating chorioamniotic membranes. It is an effective method of labour induction for multiparous women with favourable cervices but onset of labour is unpredictable. But routine amniotomy should not be performed if labour is progressing normally and there is no evidence of foetal compromise. The indication for amniotomy; the amount, colour and odour of amniotic fluid; FHR features prior to amniotomy; foetal response following the procedure; cervical status; and foetal station should all be documented in the medical record. During amniotomy foetal head should be well applied to cervix and no aberrant vessels or undiagnosed vasa previa should be present. Fundal or suprapubic pressure or both can be applied to avoid disengagement of foetal head during artificial rupture of membrane (ARM), and palpate the presenting part until it rests against the cervix to avoid prolapse of cord. Risks of amniotomy include cord prolapse (especially in unengaged head), caesarean section, cord compression, intra-amniotic infection, foetal injury and

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bleeding from undiagnosed vasa previa. Foetal heart rate should be watched immediately before and after amniotomy. Membrane Stripping It is a safe method to hasten the onset of spontaneous labour and lowers the risk of postterm pregnancy. By inserting a gloved finger beyond the internal cervical os and twisting the finger 360° along the lower uterine segment, the chorioamniotic membrane is digitally separated from the cervix wall and lower uterine segment leading to release of endogenous prostaglandin-F2-alpha. It is typically performed from 39 weeks onwards before pharmacological induction if there is no contraindication to vaginal delivery as it will reduce IOL. Membrane stripping is however not routinely recommended as there is no evidence that it improves foetomaternal or perinatal outcomes. Inform the women about discomfort and possibility of bleeding post procedure. Routine sweeping after 38 weeks reduced the number of pregnancies beyond 41 weeks with 8 sweepings to reduce 1 induction. Extra-Amniotic Saline Infusion Saline is injected by a catheter in the extra-amniotic space resulting in more prostaglandin release. The Cochrane review on mechanical methods for inducing labour does not support the use of extra-amniotic infusion as it has no evident advantage over other methods. Other Approaches There are few other alternative approaches that have been tried for cervical ripening and labour induction like nipple stimulation, sexual intercourse, hot baths/enemas and acupuncture with varying degrees of success. Castor oil has been used in India but literature is sparse regarding it. Due to little research on safety and/or efficacy and availability of established and safer alternatives, these alternative procedures are still not recommended.

6.1.2 Pharmacologic Techniques Option of pharmacologic agents for labour induction and cervical ripening depends on their effectiveness, safety, ease of procurement, storage and administration, cost and patient satisfaction [8, 13, 14]. Pharmacologic agents used for this purpose include: 1. Oxytocin 2. Prostaglandins (PGs) – prostaglandin E1 (PGE1) analogue (misoprostol); prostaglandin E2 (PGE2) analogue (prepidil, cervidil) 3. Uncommon or experimental pharmacologic agents: (a) Mifepristone (b) Relaxin (c) Nitric oxide (NO) donors (d) Hyaluronidase

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Oxytocin The most popular and well-proven method of inducing and augmenting labour is oxytocin administration. Oxytocin is an effective labour-inducing agent in women with favourable cervical score but is not a suitable agent for cervical ripening. ACOG and SMFM recommend pre-induction cervical ripening by prostaglandins followed by oxytocin to be more effective than oxytocin alone as a method of induction. Mechanism of action: Exogenous oxytocin induces uterine contractions in the same way that natural endogenous oxytocin does during spontaneous childbirth. Signalling events are triggered by receptor activation, which typically raise intracellular calcium levels, causing contractions to occur. Myometrial responsiveness increases with increasing gestational age until 34  weeks, when it plateaus until spontaneous labour begins, at which point it dramatically increases. Increases in myometrial oxytocin receptor binding sites are the primary cause of increased myometrial sensitivity. Route and dosage: Intravenous is the most commonly administered route of oxytocin with a plasma half-life of 3–5  min and steady-state concentration and maximal uterine contractile response attained by approximately 40 min. Oxytocin can be titrated based on contraction frequency and strength. Uterine contractions are not associated with changes in plasma oxytocin concentration, and hypocontractile labour does not appear to be the result of an oxytocin deficiency. Oxytocin dosing regimens vary widely, differing in initial dose, incremental increase, dosing interval and maximum dose. The regimens are categorised as either low (physiological) or high (pharmacological) dose. Both regimens are acceptable and found to be equally effective in establishing adequate labour patterns and none has been yet proved superior to the other in achieving optimal maternal and perinatal outcomes. Although the data suggest that the length of labour and some outcomes, such as chorioamnionitis, may be lower with higher-dose regimens, the evidence is insufficient to draw a firm conclusion about whether using a high-dose versus a low-dose regimen affects the caesarean birth rate or other maternal or neonatal outcomes. High dose include starting at 6 mU/min and increasing by 6 mU/ min at 20- or 40-min interval. Low dose include starting at 2 mU/min and increasing to 4, 8, 12, 16, 20 and 25 mU/min at 15-min interval. Ideally it should be given with an infusion pump that can deliver a precise flow rate for minute-by-minute control. Obese women require higher doses compared to normal weight controls. Maximum dose for augmentation of labour: If uterine contractions are not adequate and foetal heart rate is reassuring and labour has arrested, oxytocin up to 48 mU/min is safe. Side effects: Although oxytocin has a good safety profile, side effects associated with its inadvertent use or with higher doses include: • Tachysystole. • Hyponatremia. • Hypotension.

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• Oxytocin owing to its antidiuretic property, when administered along with large volume of fluid, can lead to water intoxication leading to convulsions and coma. • If oxytocin needs to be given in high doses for a prolonged duration, preferable is to increase the concentration rather than increasing the drip rate. Prostaglandins Mechanism of action: They act by increasing the activity of proteases that degrade the extracellular matrix to facilitate cervical ripening and dilation. Contraindications: Prostaglandins should not be used for labour induction in following circumstances: • In term pregnancies with a prior caesarean birth. • Other prior major uterine surgeries like intramyometrial myomectomy or repair of major congenital uterine anomalies, because there is risk of uterine rupture. • Pre-existing regular uterine activity. This is a relative contraindication because of risk of excessive uterine activity. Hence, either delay or avoid prostaglandin use if good uterine contractions (2 contractions/10 min) are present. Side effects: Prostaglandin use is associated with following side effects: • Uterine tachysystole (30%) with or without foetal heart rate changes. • Systemic side effects like fever, chills, vomiting and diarrhoea (5%). Treatment is symptomatic. The frequency of these side effects depends upon the type of prostaglandin, dose and route of administration. Specific agents: The optimal type, route, frequency and dose of prostaglandins for cervical ripening and labour induction have not been determined despite many studies on their use. Few important points that have been derived from various trials include: • Local administration via the vagina or endocervix is associated with a lower frequency of side effects than oral administration. • Intravaginal misoprostol is associated with the highest probability of achieving vaginal delivery within 24 h. • Intravaginal PGE2 is more likely to result in vaginal delivery within 24 h than endocervical PGE2, but both preparations are associated with similar rates of caesarean delivery and tachysystole. PGE1 Analogue: Misoprostol

• Cervical ripening and induction of labour are an off-label use of misoprostol; however, the ACOG has approved its use for cervical ripening and labour induction in inpatient setting. • It is available as 100, 200, 25 μg tablets. • Various routes available for its administration are vaginal/oral/buccal or sublingual. Either route is reasonable, and existing data do not imply that one route is

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clearly superior to the other. Temperature stability and low cost are its definite advantages. Oral and sublingual routes are rapidly absorbed. Peak at approximately 30 min. Buccally or vaginally: 70–80 min. Oral misoprostol. –– Half-life: 20–40 min. –– Shorter duration of action: 2 h. Vaginal duration of action: 4 h. Sublingual duration of action: 3 h. 25 μg every 4–6 h vaginally. The World Health Organisation (WHO) has recommended oral 25 μg misoprostol every 2 h. It can disrupt uterine scar in women with previous uterine scar and can cause uterine tachysystole with or without foetal heart rate abnormalities, so contraindicated in patients with vaginal birth after caesarean (VBAC). Maintain a gap of at least 4 h for oxytocin administration after the last dose of misoprostol.

PGE2 Analogue: Dinoprostone

• Dinoprostone ripens the cervix by directly softening cervix, relaxing its smooth muscles and producing uterine contractions. • It comes in two preparations for cervical ripening: prepidil (gel) and cervidil. • It needs to be kept frozen until use. It does not require warming before use. • Continuous FHR and uterine activity monitoring is required during its use and for at least 15 min after its removal. • Oxytocin should be delayed for at least 30–60 min after removal. • Intravaginal prostaglandin E2 (PGE2) is more likely to result in vaginal delivery within 24 h versus endocervical PGE2; both are associated with similar rates of CS and tachysystole. • The table below summarises and compares the commonly used pharmacologic agents for labour induction and cervical ripening [8, 13–16].

Route Preparations/ formulations

Oxytocin Intravenous Available in ampule form: 10 units, 20 units

Misoprostol Intravaginal/oral/ sublingual/buccal Available in tablet form: 25 μg, 100 μg, 200 μg

Dinoprostone Intravaginal/ intracervical Available in gel form, containing 0.5 mg dinoprostone, and as vaginal insert, containing 10 mg dinoprostone (releases medication at the rate of 0.3 mg/h)

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Induction of Labour Oxytocin The biologic half-life is approximately 10–12 min; 3–4 half-lives are needed to reach physiologic steady state (30–60 min) at which time full effect of dosage on the uterine response can be assessed In low-dose regimen: 0.5–1 mU/min or 1–2 mU/min; in high dose regimen: 6 mU/ min In low-dose regimen: 20–40 mU/min; in high-dose regimen: 36–42 mU/min Every 15–60 min N/A

Misoprostol Half-life depends on route of administration: vaginal—20 min; oral—8 min; sublingual—11 min; peak action is attained by vaginal route in 1–2 h, and by oral route in 30 min

Dinoprostone Half-life is 15–30 min; peak action is attained in 17 h

Intravaginal: 25 μg; oral: 25–50 μg; sublingual: 25–50 μg

Intravaginal: 1 mg dinoprostone; intracervical: 0.5 mg dinoprostone

Up to 6 doses

Maximum of 3 doses in 24 h

Every 4–6 h Oxytocin should be delayed until at least 4 h after last dose when administered vaginally and at least 2 h after the last dose when administered orally

Uterine tachysystole (dose related); hyponatremia due to water intoxication Inexpensive

Uterine hyperstimulation; tachysystole

Disadvantages of use

Needs refrigeration; patient needs to lie in recumbent position

Contraindications

Any contraindication to vaginal birth

Higher risk of tachysystole and meconium passage; risk of uterine rupture in vaginal birth after caesarean (VBAC) Any contraindication to vaginal birth; glaucoma; renal or hepatic failure; previous caesarean delivery

Every 6–12 h Intravaginal: oxytocin should be delayed for at least 30–60 min after removal of insert; intracervical: oxytocin is withheld for at least 6 h since the last dose Uterine hyperstimulation (1%); fever; vomiting; diarrhoea Intracervical: lesser risk of hyperstimulation; intravaginal: easily placed and removed; one-time dosing Expensive; needs refrigeration; difficult to administer intracervical dose

Pharmacodynamics

Initial dose

Maximum dosage

Dosing interval Use with oxytocin if needed

Side effects

Advantages of use

Inexpensive; stable at room temperature

Any contraindication to vaginal birth; glaucoma; renal or hepatic failure

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Foetal surveillance after prostaglandin use: • Let the women remain recumbent for half an hour after prostaglandin administration. • Continuous foetal heart monitoring should be done for at least 1 h after insertion. In various trials, outpatient PGs have also been tried in low-risk women and patients have reported more satisfaction. • Monitor vital signs of mother. • Do not administer in cases with foetal heart abnormalities as we cannot immediately terminate the effects of uterine activity. If tachysystole happens, try to remove the PG from the vagina and intravenous nitroglycerin can be used. Spray of nitroglycerin is under trial for this use. • Oxytocin can be given 6 h after PGE2 gel and 30 min after removal of insert. Uterine tachysystole without foetal heart rate changes can happen with PGE2. Uncommon or Experimental Pharmacologic Agents Mifepristone

Mifepristone has mostly been utilised in clinical settings to aid in the safe performance of medical abortion. Its usage as a cervical ripening agent before induction has been studied in term labour and compared to placebo, but till now mifepristone has been considered investigational and is not routinely recommended for labour induction. NO Donors

Studies observed that the level of cervical NO metabolite was higher at the start of uterine contractions and quite low in postterm pregnancy. As a result, NO donors were proposed for cervical ripening. They act by inducing cervical Cyclooxygenase-2 (COX-2) and initiating cervical ultrastructure rearrangement. The two agents used are isosorbide mononitrate and glyceryl trinitrate. These and few other pharmacologic agents have been tried for cervical ripening and labour induction, but due to paucity of data regarding their safety and efficacy none of these can be recommended as an evidence-based approach to labour induction.

7 Outcome of Labour Induction 7.1 Labour Progress In induced labour, the latent phase usually lasts longer as compared to that in spontaneous labour. However, after entering into active labour the course of women who have been induced appears to be comparable to that of those who undergo spontaneous labour.

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7.2 Failed Induction There has not been yet an agreement on what constitutes a failed induction. The workshop on preventing the first caesarean delivery, convened by the United States National institute of child health and human development (NICHHD), SMFM and ACOG, defined failed induction as: failure to generate regular (every 3 min) contractions and cervical change after at least 24  h of oxytocin administration, with artificial rupture of membranes as feasible and safe. With a reassuring maternal and foetal status 18–24 h after cervical ripening and membrane rupture along with oxytocin administration, we label it as failed induction and recommend caesarean section. A large observational study in 2018 found that 96.4% nulliparous women reached active phase in 15 h and despite prolonged active phase of more than 18 h, 40% women delivered vaginally, though women with prolonged latent phase can land in postpartum haemorrhage and chorioamnionitis. It is also a sensible approach to reserve the term of failed induction when the latent phase has lasted for an extended period of time and it is doubtful that the active phase will be completed or that vaginal delivery will be achieved, according to the clinician’s view. When estimating the length of induction or diagnosing a failed induction, the time spent on cervical ripening is not taken into account.

7.3 Unsuccessful Induction Change of method can be done after 24–48 h, or National Institute for Health and Care Excellence (NICE) suggests a rest period and further attempting induction or caesarean.

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8 Timing of Induction of Labour in Specific Circumstances [1–6] S. no. 1

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Indication of induction Preterm prelabour rupture of membranes

Term prelabour rupture of membranes

Timing of induction NICE (2021) • Before 34 + 0 weeks: Expectant management, unless any additional obstetric indications • After 34 + 0 weeks: Expectant management until 37 + 0 weeks or induction of labour; shared decision-making considering risks to the woman, risks to the baby, local availability of neonatal intensive care unit (NICU) facilities and the woman’s individual circumstances and her preferences • After 34 + 0 weeks (and had a positive group B Streptococcus test at any time in current pregnancy): Immediate induction of labour/delivery ACOG (2020) • 34 0/7–36 6/7 weeks of gestation: Expectant management or proceed towards delivery • 24 0/7–33 6/7 weeks of gestation: Expectant management • Less than 23–24 weeks of gestation: Expectant management or induction of labour with patient counselling and considering neonatology and maternal–foetal medicine consultation FOGSI-ICOG GCPR (2018) • After 34 weeks: Induction of labour after discussing risks of sepsis to the woman and the baby, complications of prematurity and availability of NICU facilities • Before 34 weeks and after the period of viability: Expectant management till 34 weeks, unless additional obstetric indications NICE (2021) • At or after 37 + 0 weeks: Offer a choice of expectant management for up to 24 h or induction of labour as soon as possible after discussing the benefits and risks of these options with the woman, and taking into account her individual circumstances and preferences • At or after 37 + 0 weeks (and had a positive group B Streptococcus test at any time in current pregnancy): Immediate induction of labour/delivery ACOG (2020) • 37 0/7 weeks of gestation or more: Proceed towards delivery FOGSI-ICOG GCPR (2018) • At or more than 37 weeks: Induction of labour is recommended

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Indication of induction Hypertensive disorders in pregnancy

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Timing of induction NICE (2019) Gestational hypertension or preeclampsia without severe features* • Before 37 0/7 weeks: Expectant management • At or beyond 37 0/7 weeks: Induction of labour/delivery Preeclampsia with severe features* • Before 34 0/7 weeks: Expectant management • At or beyond 34 0/7 weeks: Induction of labour/delivery Chronic hypertension with no additional maternal or foetal complications supporting earlier delivery* • Before 37 0/7 weeks: Expectant management • At or beyond 37 0/7 weeks: Induction of labour/delivery *During expectant management, immediate delivery is recommended at any time in case of maternal or foetal compromise ACOG Gestational hypertension or preeclampsia without severe features* (ACOG 2020) • Before 37 0/7 weeks: Expectant management • At or beyond 37 0/7 weeks: Induction of labour/delivery Preeclampsia with severe features* (ACOG 2020) • Before 34 0/7 weeks: Expectant management • At or beyond 34 0/7 weeks: Induction of labour/delivery Chronic hypertension (ACOG 2019) Chronic hypertension with no additional maternal or foetal complications supporting earlier delivery* • Before 38 0/7 weeks and not on maintenance antihypertensive medications: Expectant management • Before 37 0/7 weeks and on maintenance antihypertensive medications: Expectant management • At or beyond 37 0/7 weeks: Induction of labour/delivery Chronic hypertension with severe acute hypertension, not controlled with antihypertensives or with superimposed preeclampsia with severe features* • Before 34 0/7 weeks: Expectant management • At or beyond 34 0/7 weeks: Induction of labour/delivery *During expectant management, immediate delivery is recommended at any time in case of maternal or foetal compromise FOGSI-ICOG GCPR (2018) Preeclampsia: Induction of labour at 37 weeks or earlier if indicated for maternal or foetal compromise Gestational hypertension: Expectant management can be considered beyond 37 weeks if at low risk of adverse outcomes

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D. Rafat and F. Azhar Indication of induction Hyperglycaemic disorders of pregnancy

Timing of induction NICE (2020) Women with type 1 or 2 diabetes and no other complications • Induction of labour/delivery: 37 0/7–38 6/7 weeks Women with type 1 or 2 diabetes and maternal or foetal complications • Induction of labour/delivery: Before 37 0/7 weeks Women with gestational diabetes and no other complications • Induction of labour/delivery: At 40 6/7 weeks Women with gestational diabetes and maternal or foetal complications • Induction of labour/delivery: Before 40 0/7 weeks ACOG (2018) Women with gestational diabetes, controlled on diet and exercise and no other complications • Induction of labour/delivery: 40 6/7 weeks Women with gestational diabetes, controlled on medications and no other complications • Induction of labour/delivery: 39 0/7–39 6/7 weeks Women with poorly controlled gestational diabetes • Induction of labour/delivery: 37 0/7–38 6/7 weeks Women who fail in-hospital attempts to improve glycaemic control or who have abnormal antepartum foetal testing • Induction of labour/delivery: 34 0/7–36 6/7 weeks FOGSI-ICOG GCPR (2018) Women with gestational diabetes, controlled on diet and exercise and no other complications • Induction of labour/delivery: Not before 39 weeks Women with gestational diabetes, controlled on medications and no other complications • Induction of labour/delivery: 38 weeks *Management of women with uncontrolled diabetes should be individualised

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Indication of induction Foetal growth restriction

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Timing of induction ACOG (2020) and SMFM Isolated fetal growth restriction (FGR) with estimated fetal weight (EFW) between the third and tenth percentile and normal umbilical artery Doppler • Induction of labour/delivery: 38–39 weeks Isolated FGR with EFW less than the third percentile and normal umbilical artery Doppler • Induction of labour/delivery: 37 weeks FGR with elevated umbilical artery Doppler of greater than the 95th percentile for gestational age • Induction of labour/delivery: 37 weeks FGR with absent end-diastolic velocity in umbilical artery Doppler • Delivery: Between 33 and 34 weeks FGR with reversed end-diastolic velocity in umbilical artery Doppler • Delivery: Between 30 and 32 weeks FIGO (2021) Isolated mild small for gestational age (SGA) (EFW at third– ninth percentile) with no additional abnormalities (i.e. normal fluid and Doppler studies) • Induction of labour/delivery: 37–39 weeks Isolated severe SGA (EFW