SOGC Clinical Practice Guideline No. 381 Assisted Vaginal Birth 2019 PDF

SOGC CLINICAL PRACTICE GUIDELINE It is SOGC policy to review the content 5 years after publication, at which time the document may be re-affirmed or revised to reflect emergent new evidence and changes in practice....

SOGC CLINICAL PRACTICE GUIDELINE It is SOGC policy to review the content 5 years after publication, at which time the document may be re-affirmed or revised to reflect emergent new evidence and changes in practice. No. 381, June 2019 (Replaces No. 148, Aug. 2004) This consensus statement is the second in a 4-part series on labour and delivery. No. 381-Assisted Vaginal Birth This Clinical Practice Guideline has been prepared by the Society CHANGES IN PRACTICE of Obstetricians and Gynaecologists of Canada (SOGC)’s Clinical Practice Obstetrics Committee, reviewed by the Guideline 1. Encouraging safe and effective AVB by experienced and Management and Oversight Committee and approved by the skilled care providers may be a useful strategy to reduce the Board of the SOGC. rate of primary Caesarean delivery. 2. Optimizing the fetal head position prior to or during delivery Sebastian Hobson, MD, MPH, PHD, Toronto, ON can be encouraged. Krista Cassell, MD, Charlottetown, PE 3. Second stage Caesarean delivery is associated with Rory Windrim, MD, MSc, Toronto, ON short- and long-term complications, which may be taken into account when considering AVB. Yvonne Cargill, MD, Ottawa, ON 4. An international consensus for the definition of assessment of fetal station is suggested. 5. There is modification to the classifications of AVB. Clinical Practice Obstetrics Committee Members: Hussam Azzam (Co-Chair), MD, Thompson, MB; Jon Barrett, MD, Toronto, ON; Hayley Bos, MD, Victoria, BC; Kim Campbell, RM, Vancouver, BC; Krista Cassell, MD, Charlottetown, PE; Kirsten KEY MESSAGES Duckitt, MD, Campbell River, BC; Jessica Dy, MD, Ottawa, ON; 1. Encouraging safe and effective AVB by experienced and skilled Ellen Giesbrecht (Co-Chair), MD, Vancouver, BC; Lisa Graves, care providers may be a useful strategy to reduce the rate of MD, Toronto, ON; Michael Helewa, MD, Winnipeg, MB; Melanie primary Caesarean delivery. Basso, RN, Vancouver, BC; Amy Metcalfe, PhD, Calgary, AB; 2. Safe and effective AVB requires a careful assessment of the Barbara Parish, MD, Halifax, NS; Yvonne Vasilie, MD, Pointe- clinical situation, clear communication with the patient, support Claire, QC; Jennifer Walsh, MD, Calgary, AB people, and health care personnel, along with expertise in the Disclosure statements have been received from all authors. chosen method. 3. Vacuum and forceps are associated with different short- and Key Words: Assisted vaginal birth, instrumental vaginal birth, long-term benefits and risks. operative vaginal delivery, forceps, vacuum, ventouse 4. Second stage Caesarean delivery is associated with short- and long-term complications, which may be taken into account when considering AVB. 5. Obstetrical trainees should receive appropriate J Obstet Gynaecol Can 2019;41(6):870−882 comprehensive training in AVB and be deemed competent https://doi.org/10.1016/j.jogc.2018.10.020 prior to independent practice. © 2019 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved. This document reflects clinical and scientific consensus on the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed. Local institutions can dictate amendments to these opinions. They should be well-documented if modified at the local level. None of these contents may be reproduced in any form without prior written permission of the publisher. All people have the right and responsibility to make informed decisions about their care in partnership with their health care providers. In order to facilitate informed choice, patients should be provided with information and support that is evidence based, culturally appropriate, and tailored to their needs. This guideline was written using language that places women at the centre of care. The SOGC is committed to respecting the rights of all people − including transgender, gender non-binary, and intersex people − for whom the guideline may apply. We encourage health care providers to engage in respectful conversation with patients regarding their gender identity and their preferred gender pronouns to be used as a critical part of providing safe and appropriate care. The values, beliefs, and individual needs of each patient and their family should be sought, and the final decision about the care and treatment options chosen by the patient should be respected. 870  JUNE JOGC JUIN 2019 Downloaded for Anonymous User (n/a) at McMaster University from ClinicalKey.com by Elsevier on December 03, 2024. For personal use only. No other uses without permission. Copyright ©2024. Elsevier Inc. All rights reserved.  No. 381-Assisted Vaginal Birth Abstract 4. Practitioners performing assisted vaginal birth should have the knowledge, skills, and experience necessary to assess the clinical Objectives: To provide evidence-based guidelines for safe and situation, use the selected instrument, and manage complications effective assisted vaginal birth. that may arise from assisted vaginal birth (II-2B). 5. Obstetrical trainees should receive comprehensive training in Outcomes: Prerequisites, indications, contraindications, along with assisted vaginal birth and be deemed competent prior to indepen- maternal and neonatal morbidity associated with assisted vaginal birth. dent practice (III-B). 6. When assisted vaginal birth is deemed to have a higher risk of not Evidence: Medline database was searched for articles published from being successful, it should be considered a trial of assisted vaginal January 1, 1985, to February 28, 2018 using the key words “assisted birth and be conducted in a location where immediate recourse to vaginal birth,” “instrumental vaginal birth,” “operative vaginal delivery,” Caesarean delivery is available (III-B). “forceps delivery,” “vacuum delivery,” “ventouse delivery.” The quality of 7. The physician should determine the instrument most suitable to the evidence is described using the Evaluation of Evidence criteria outlined clinical circumstances and their level of skill. Vacuum and forceps in the Report of the Canadian Task Force on Preventive Health Care. are associated with different short- and long-term benefits and Validation: These guidelines were approved by the Clinical Practice risks. Unsuccessful delivery is more likely with vacuum than for- Obstetrics Committee and the Board of the Society of Obstetricians ceps (I-A). and Gynaecologists of Canada. 8. Planned sequential use of instruments is not recommended as it may be associated with an increased risk of perinatal trauma. If an Recommendations: attempted vacuum is unsuccessful, the physician should consider the risks of proceeding to an attempted forceps delivery versus 1. The need for assisted vaginal birth can be reduced by: dedicated and Caesarean section (II-2B). continuous support during labour (I-A), oxytocin augmentation of inade- 9. Restrictive use of mediolateral episiotomy is supported in assisted quate labour (I-A), delayed pushing in women with an epidural (I-A), vaginal birth (II-2B). increased time pushing in nulliparous women with an epidural (I-B), as 10. A debrief should be done with the patient and support people well as optimization of fetal head position through manual rotation (I-A). immediately following an attempted or successful assisted vaginal 2. Encouraging safe and effective assisted vaginal birth by experi- birth. If this is not possible, ideally this should be done prior to hos- enced and skilled care providers may be a useful strategy to pital discharge and include the indication for assisted vaginal birth, reduce the rate of primary Caesarean delivery (II-2B). management of any complications, and the prognosis for future 3. Safe and effective assisted vaginal birth requires expertise in the deliveries (III-B). chosen method, comprehensive assessment of the clinical situa- 11. In a subsequent pregnancy, patients should be encouraged to con- tion alongside clear communication with the patient, support peo- sider spontaneous vaginal birth. However, care planning should be ple, and health care personnel (III-B). individualized and patient preference respected (II-3B). JUNE JOGC JUIN 2019  871 Downloaded for Anonymous User (n/a) at McMaster University from ClinicalKey.com by Elsevier on December 03, 2024. For personal use only. No other uses without permission. Copyright ©2024. Elsevier Inc. All rights reserved. SOGC CLINICAL PRACTICE GUIDELINE INTRODUCTION protocols, as well as the range of skill and experience of care providers. ssisted vaginal birth (AVB) attempts to mimic spon- A taneous vaginal birth (SVB). Delivery by AVB may benefit both mothers and neonates by decreasing risks of Outcomes of randomized trials comparing vacuum with forceps should be critically appraised as there are often sig- serious morbidity associated with prolonged delays in nificant rates of protocol violations as providers can be delivery, or a Caesarean delivery late in second stage. Vari- allocated to an instrument with which they have less skill ous types of forceps or vacuum devices can be used to with or deliveries may be performed by junior trainees. safely and successfully achieve vaginal delivery, provided Furthermore, both retrospective and prospective observa- the prerequisites for AVB are met. tional studies may have unmeasured confounders that can significantly skew results. For outcomes to be weighed Care providers are expected to have the appropriate training, meaningfully, comparison must be made not to spontane- skill, and experience with any instrument used. The choice of ous vaginal delivery, but to the actual clinical options of the device will depend on the clinical situation; however, this alternate method of AVB or Caesarean delivery. Ideally, choice is primarily determined by the clinical skill and scope risk assessment would also consider the risk associated of practice of the care provider. Not all providers are with any delay in delivery that may differ for AVB and Cae- expected to achieve the same level of competence with all sarean delivery. instruments, as this can be significantly influenced by train- ing, local practices, and standards of care. Adequate patient The balance of risk of Caesarean delivery versus AVB counselling and involvement in decision making are also continuously changes as the second stage of labour pro- important aspects in the provision of AVB. gresses and depends on the clinical scenario. There may also be increased risks associated with Caesarean delivery AVB should be undertaken when there is a reasonable performed in the second stage of labour compared to chance of success, a high level of safety, and a suitable con- the first stage of labour or AVB. This includes subse- tingency plan in place. Informed consent is an essential com- quent cervical insufficiency, particularly if the fetus was ponent of AVB, as are documentation of the event and at a low station.1−4 debriefing afterwards with the care team, patient, and family. Overall, in carefully selected circumstances, both vacuum AVB has been widely studied and debated with a range of and forceps are associated with relatively low rates of seri- outcomes and safety profiles reported. Consideration must ous morbidity and mortality in both mother and baby. be given to both the maternal and neonatal risks of using either vacuum or forceps to achieve delivery. Observed Interventions that have been Shown to Promote variation in maternal and neonatal outcomes may be due Spontaneous Vaginal Birth to differences in underlying patient characteristics, multiple types of instruments being used under a variety of 1. Dedicated maternal support person. One-to-one support in labour has been shown to decrease the rate of AVB.5,6 These results are consistent through- ABBREVIATIONS out a variety of obstetrical settings, hospital condi- AVB assisted vaginal birth tions, pregnancy risk factors, and differing levels of CI confidence interval professional training in the persons who provided CPD cephalopelvic disproportion support. This practice should be encouraged in all NICU neonatal intensive care unit maternity care sites. OA occiput anterior 2. Use of intermittent auscultation for low risk labour. A OASIS obstetrical anal sphincter injury 2017 Cochrane review suggests use of continuous elec- OP occiput posterior tronic fetal monitoring in low-risk women in labour is asso- OR odds ratio ciated with an increase in both Caesarean delivery and OT occiput transverse AVB when compared with intermittent auscultation.7 PPH postpartum hemorrhage 3. Delayed pushing with epidural. Epidural use is associ- PTSD post-traumatic stress disorder ated with an increased rate of AVB. The 2017 Cochrane review on this subject has shown that delaying pushing RR relative risk with an epidural when there is no urge to push reduces SVB spontaneous vaginal birth the total duration of pushing and increases the rates of 872  JUNE JOGC JUIN 2019 Downloaded for Anonymous User (n/a) at McMaster University from ClinicalKey.com by Elsevier on December 03, 2024. For personal use only. No other uses without permission. Copyright ©2024. Elsevier Inc. All rights reserved.  No. 381-Assisted Vaginal Birth successful vaginal birth but may increase the incidence of forceps-assisted deliveries (9.6% vs 3.2%).13 Concurrently, low Apgar scores.1,3 In nulliparous patients, a 2018 ran- the rates of primary Caesarean delivery have been climbing domized clinical trial of 2404 patients demonstrated that and many authorities have raised concerns over these immediate compared to delayed pushing was associated trends. International data would suggest that these changes with similar rates of SVB, lower rates of chorioamnionitis, are being seen on a global scale.14 PPH, and neonatal acidemia.8 There were, however, higher rates of OASIS in the immediate pushing group. Currently, As one approach, in order to ameliorate increasing rates the evidence is conflicting in this area. of Caesarean delivery, the American College of Obste- 4. Increasing the time pushing with epidural. tricians and Gynecologists and the Society for Mater- Although there are geographic variations within nal-Fetal Medicine have recently begun advocating for centres across Canada, contemporary obstetrical the increased use of AVB to achieve delivery.15 Strate- practice has generally defined a prolonged second gies and evaluations of approaches to achieve this end- stage as pushing in labour with an epidural as goal are underway,16,17 and the current primary chal- >3 hours for nulliparous women and >2 hours for lenge of AVB hinges on opportunities to promote ade- parous women.4,9 One randomized trial in 2016 quate skills and training.18,19 It is now widely accepted showed that for nulliparous women, if the duration that obstetrical trainees should receive appropriate com- of active pushing is extended by 1 hour beyond this prehensive training in AVB and be deemed competent convention that there is a reduced risk of Caesarean prior to independent practice.16,20,21 This not only delivery without increases in adverse maternal or maintains a high standard of patient care and improves perinatal outcomes.10 Regardless of definitions and outcomes, it also serves to maintain the highly skilled limits applied, a pragmatic approach to prolonged Art of Obstetrics in the next generation of care second stage and management is advised. providers.22 5. Manual rotation. Manual rotation from an OT or OP position to a more optimal position has been correlated Recommendations with decreased use of vacuum or forceps in second 2. Encouraging safe and effective assisted vaginal birth stage and may be up to 90% effective in achieving rota- by experienced and skilled care providers may be a tion to OA.11,12 In most cases, manual rotation is useful strategy to reduce the rate of primary Caesar- attempted after reaching full dilation; however, in certain ean delivery (II-2B). clinical scenarios it may be required prior to full dilation 3. Safe and effective assisted vaginal birth requires to facilitate the progress of labour. Manual rotation to expertise in the chosen method, comprehensive optimize the fetal head position may also aid subsequent assessment of the clinical situation alongside clear AVB if required. communication with the patient, support people, and health care personnel (III-B). Recommendation 4. Practitioners performing assisted vaginal birth should 1. The need for assisted vaginal birth can be reduced have the knowledge, skills, and experience necessary by: dedicated and continuous support during labour to assess the clinical situation, use the selected instru- (I-A), oxytocin augmentation of inadequate labour ment, and manage complications that may arise from (I-A), delayed pushing in women with an epidural assisted vaginal birth (II-2B). (I-A), increased time pushing in nulliparous women 5. Obstetrical trainees should receive comprehensive with an epidural (I-B), as well as optimization of fetal training in assisted vaginal birth and be deemed com- head position through manual rotation (I-A). petent prior to independent practice (III-B). Indications for Assisted Vaginal Birth Assisted Vaginal Birth Over Time  Maternal conditions precluding repetitive Valsalva AVB rates in Canada have declined from 2002-2003 manoeuvres including, but not limited to, maternal car- (15.7%), 2005-2006 (14.3%), and 2011-2012 (rural areas diac disease (New York Heart Association class III or 8.6%, urban areas 10.6%). This downward trend was IV), severe respiratory disease, cerebral arteriovenous observed for both vacuum and forceps deliveries, malformation or proliferative retinopathy, as well as neu- and data available from 2010-2011 suggest the rate of rologic diseases such as myasthenia gravis or spinal cord vacuum-assisted deliveries was three-times the rate of injury at risk of autonomic dysreflexia. JUNE JOGC JUIN 2019  873 Downloaded for Anonymous User (n/a) at McMaster University from ClinicalKey.com by Elsevier on December 03, 2024. For personal use only. No other uses without permission. Copyright ©2024. Elsevier Inc. All rights reserved. SOGC CLINICAL PRACTICE GUIDELINE  Delayed progress in the second stage of labour due to High malposition or inadequate fetal descent despite maximal  The fetal head is not engaged with station above the maternal effort and effective uterine contractions. ischial spines. Contemporary practice does not support  Abnormal fetal heart rate tracing. the use of vacuum or forceps delivery at high station.23 Contraindications to Assisted Vaginal Birth Accurate Examination and Measurement of Station Absolute An important concept in AVB is the accurate and stan-  Non-vertex presentation, unless forceps are used for dardized examination of the maternal bony pelvis, soft tis- face presentation or the after-coming head in vaginal sues, and fetus, along with their spatial relationship and breech delivery. temporal changes during labour and delivery. In order to  Unengaged head, with more than one-fifth of the fetal safely and effectively perform AVB, all practitioners should head palpable abdominally above the pubic brim. be skilled in this comprehensive mandatory assessment  Incomplete cervical dilation. including:  Uncertainty of the fetal head position.  Suspected CPD. 1. Abdominal examination: Palpation of the uterus, fetal  Fetal coagulopathy, thrombocytopenia, or brittle skeletal lie, presenting part, descent of the head into the mater- dysplasia. nal pelvis (measured in fifths above the pubic brim),  Inability to progress to timely Caesarean delivery should and assessment of the maternal bladder size requiring the AVB be unsuccessful. voiding/emptying. Ultrasound examination may be used as an adjunct to physical examination, particularly in the preparation for rotational AVB.24 Relative 2. Vaginal examination:  Vacuum delivery for fetal prematurity, particularly 30 kg/m2 maternal soft tissue entrapment, avoiding slippage or pop- b. Estimated fetal weight >4000 g or clinical suspicion offs of the vacuum, and controlling the rate of descent and of macrosomia delivery of the head.32−34 Unless clinically indicated, rou- c. OP or OT position tine use of episiotomy is no longer recommended to facili- d. Mid-cavity delivery tate AVB.35 5. Analgesia: Regional anesthesia with spinal, epidural, or In regard to AVB for malposition, a birth cohort study of pudendal block may be suitable options. over 1000 deliveries in New Zealand suggested that in JUNE JOGC JUIN 2019  875 Downloaded for Anonymous User (n/a) at McMaster University from ClinicalKey.com by Elsevier on December 03, 2024. For personal use only. No other uses without permission. Copyright ©2024. Elsevier Inc. All rights reserved. SOGC CLINICAL PRACTICE GUIDELINE experienced hands, rotational forceps successfully deliv- incontinence between women who had Caesarean births ered over 95% of infants with maternal trauma rates that performed either before or during labour.40 Forceps deliv- are both low and similar to vacuum delivery.36 This was ery did not significantly increase the risk of urinary inconti- also supported by a retrospective study in the United King- nence (RR 1.5; 95% CI 1.0−2.3) compared with dom of 1291 consecutive births with malposition in the spontaneous vaginal delivery. A 5-year follow-up study of a second stage of labour. The authors demonstrated that randomized controlled trial in the United Kingdom com- Kielland’s rotational delivery was more successful than paring vacuum versus forceps did not find any major dif- autorotational vacuum (96% vs. 78%) with no significant ferences in outcomes.41 Urinary incontinence was reported differences in PPH, OASIS, or admission to the NICU.37 by 47%, bowel habit urgency was reported by 44%, and A 2013 prospective study suggested simple manual rota- loss of bowel control “sometimes” or “frequently” by 20% tion of posterior or transverse fetuses at full dilation results of women. No significant differences were found in terms in decreased operative delivery rate.38 of either bowel or urinary dysfunction between the vacuum and forceps delivery groups. OASIS includes both partial and complete third- and fourth-degree tears of the perineum. The overall incidence Pelvic floor morbidity 3 years after instrumental versus of OASIS reported in the literature also varies across sour- Caesarean delivery in the second stage of labour was ces due to differences in the definition and accurate recog- assessed in a prospective cohort of 393 women.42 Long- nition of the condition, as well as the impact of episiotomy. term urinary incontinence was greater in the instrumental It is generally accepted, however, that OASIS rates are delivery group as compared to the Caesarean delivery higher with AVB than with SVB and are higher with for- group (10.5% vs 2.0%; OR 5.37; 95% CI, 1.7−27.9). ceps than with vacuum delivery. A recent review suggests There were no significant differences in anorectal or sexual an OASIS incidence of between 4% and 6.6% of all vaginal symptoms between the two groups. A subsequent delivery births, including those by AVB.39 did not increase the risk of pelvic floor symptoms at 3 years in either group. Another longitudinal cohort of 1011 U.K. OASIS can cause significant perineal pain, which can lead women 5−10 years after vaginal or Caesarean birth com- to urinary retention or defecation problems in the early pared pelvic floor symptoms between groups.43 Compared postpartum period and dyspareunia and sexual dysfunction with Caesarean without labour, SVB was associated with a in the long term. Damage to the anal sphincter complex or significantly greater odds of stress incontinence (OR 2.9; pudendal nerve can also lead to the many manifestations 95% CI 1.5−5.5) and prolapse to or beyond the hymen of anal incontinence. Women having any type of vaginal (OR 5.6; 95% CI 2.2−14.7). AVB significantly increased birth compared with a Caesarean delivery have an the odds for all pelvic floor disorders, especially prolapse increased risk of developing anal incontinence. A large (OR 7.5; 95% CI 2.7−20.9). Their results suggested that meta-analysis suggested that the risk of symptoms in the 6.8 additional AVBs or 8.9 SVBs, relative to Caesarean first postpartum year ranged from a one third increased births, would lead to 1 additional case of prolapse. risk for SVB (OR 1.32; 95% CI 1.04−1.68) to a doubling of risk with forceps (OR 2.01; 95% CI 1.47−2.74). How- Postpartum PTSD has steadily gained recognition as a ever, when compared to SVB, instrumental deliveries clinical entity. A recent Canadian study suggested an inci- resulted in more symptoms of anal incontinence (OR 1.47; dence of clinically diagnosed PTSD in up to 7.6% within 95% CI 1.22−1.78), which was statistically significant for the first 4 weeks postpartum, with another 16.6% of forceps deliveries (OR 1.5; 95% CI 1.19−1.89) but not for women reporting partial symptoms.44 While some studies vacuum deliveries (OR 1.31; 95% CI 0.97−1.77).28 suggest a delivery that is perceived by the woman to be traumatic, including an AVB or unplanned Caesarean Urinary tract symptoms can occur secondary to nerve delivery, may lead to PTSD and may even deter future injury and pelvic floor weakness in the form of urinary child-bearing,45−47 a recent large population-based Nor- incontinence or pelvic organ prolapse. Urinary stress wegian study does not suggest that mode of delivery is a incontinence is common in women during the early post- key factor in the development of postpartum PTSD.48 partum period. A Canadian study suggested urinary incon- More research is required in this area. tinence rates at 6 months postpartum of 26%, irrespective of mode of delivery. Spontaneous vaginal delivery was Importantly, it is now emerging that compared to alterna- associated with a higher incidence of urinary incontinence tive modes of delivery, second stage Caesarean delivery is (RR 2.1; 95% CI 1.1−3.7) compared with Caesarean deliv- associated with increased risk of subsequent preterm birth ery. There was no significant difference in rates of both