Incidence of obstetric anal sphincter injuries after training to protect the perineum: cohort study

Birth and Regulation of head Extension to Guide Manual perineal Assistance (BREGMA) study: a prospective cohort study

BACKGROUND

The exact positioning of the dominant hand at the time of manual perineal protection (MPP) is not clearly specified. The main aim of this work was to identify the place on the perineum where pressure needs to be applied to achieve optimal forward fetal head displacement away from the anal sphincters using the bregma to posterior fourchette distance (BFD) and the perineal body length (PBL).

METHODS

This was a two-center prospective cohort study. Term cephalic singleton nulliparous women having spontaneous vaginal delivery were considered eligible for recruitment into the study. Once crowning was diagnosed and just prior the initiation of manual perineal protection (MPP) or cutting an episiotomy, the BFD and PBL were measured using a standardized measurement protocol.

RESULTS AND DISCUSSION

A total of 100 women (50 women in each center) were recruited into the study. The overall mean BFD was 2.8 ± 0.5 cm. The overall mean PBL was 4.4 ± 0.8 cm. There were no statistically significant differences between the measurements taken in both units regarding BFD or PBL (p = 0.81 and 0.10 respectively). There was a weak correlation between both measurements. Based on our measured parameters, it seems that the most effective point to apply perineal pressure to displace the head away from the anus is approximately 1 - 1.5 cm anterior to the anal margin.

CONCLUSION

Measurements generated by this study will form the bases of future biomechanical studies to confirm their validity.

Efficacy of intrapartum bundles and interventions in reducing vaginal delivery-related perineal trauma: a systematic review

OBJECTIVE

The aim of this systematic review is to summarize the current evidence on preventive interventions and bundles, including combinations of multiple techniques, aimed at reducing vaginal delivery-related perineal injury.

METHODS

A systematic research of literature was independently conducted on different databases (PubMed, MEDLINE, EMBASE) by the authors, using a combination of the identified keywords and index terms as per current PRISMA guidelines. The research was restricted to papers published in English starting by 2000. Similar papers as previously published reviews and metanalysis satisfying the inclusion criteria were used as cross-reference to check for potential further inclusions.

FINDINGS

In total 14 papers have been identified to be included in our review, divided into 2 randomized controlled trials and 12 cohort studies (4 prospective cohort studies, 6 retrospective cohort studies, 1 prospective case-control study and 1 multicenter step-wedge cluster study).

CONCLUSIONS

Bundles and interventions, including combinations of techniques and tools aimed at enhancing intrapartum perineal care are effective in reducing adverse perineal outcome after vaginal delivery. Most common features include training programs for labor professionals, pushing instructions and communication, hands-on technique for both reducing speed of delivery and perineal support, and restrictive use of medio-lateral episiotomy.

Obstetric anal sphincter injuries during instrumental vaginal delivery: An observational study based on 18-years of real-world data

OBJECTIVE

To determine the prevalence and secular trends of obstetric anal sphincter injuries (OASIS) in vacuum and forceps deliveries in Norway, both with and without episiotomy.

DESIGN

Population-based real-world data collected during 2001-2018.

SETTING

Medical Birth Registry Norway.

POPULATION OR SAMPLE

Nulliparous women with singleton foetuses in a cephalic presentation delivered by either vacuum or forceps (n = 70 783).

METHODS

Logistic regression analyses were applied to the OASIS prevalence in six 3-year time periods. Both crude odds ratios and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were determined.

MAIN OUTCOME MEASURES

OASIS prevalence.

RESULTS

The OASIS prevalence in vacuum and forceps deliveries decreased from 14.8% during 2001-2003 to 5.2% during 2016-2018. The overall reduction between the first and last 3-year time period was 61% (aOR = 0.39, 95% CIs = 0.35-0.43). The only exception to this decreasing trend in OASIS was found in forceps deliveries performed without an episiotomy. The OASIS prevalence was approximately twofold higher in forceps compared to vacuum deliveries (aOR = 1.92, 95% CIs = 1.79-2.05). Performing either a mediolateral or lateral episiotomy was associated with a 45% decrease in the prevalence of OASIS relative to no episiotomy (aOR = 0.55, 95% CIs = 0.52-0.58).

CONCLUSIONS

Opting for vacuum rather than forceps delivery in conjunction with a mediolateral or lateral episiotomy could significantly lower the OASIS prevalence in nulliparous women.

Guideline No. 457: Obstetrical Anal Sphincter Injuries (OASIS) Part I: Prevention, Recognition, and Immediate Management

OBJECTIVE

The purpose of this guideline is to promote recognition and preventive strategies for obstetrical anal sphincter injuries. Furthermore, it provides guidance on primary repair and immediate postpartum management for obstetrical anal sphincter tears in order to minimize further negative sequelae.

TARGET POPULATION

All patients having a vaginal delivery and those who have sustained an obstetrical anal sphincter injury.

OUTCOMES

Certain preventive strategies have been associated with lower rates of obstetrical anal sphincter injuries (e.g., fetal head flexion and control, appropriate use of mediolateral episiotomy). Management strategies, including appropriate diagnosis and repair of obstetrical anal sphincter injuries, antibiotic prophylaxis, and bowel and bladder function management can decrease associated short- and long-term complications.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline may increase detection, prevention, and appropriate management of obstetrical anal injuries, thus limiting the future burden associated with these injuries. Implementation of the recommended classification of obstetrical anal sphincter injuries will improve national and international research efforts.

EVIDENCE

Published literature was retrieved through searches of PubMed, Ovid, Medline, Embase, Scopus, and the Cochrane Library from September 1, 2014, through November 30, 2023, using appropriate MeSH terms (delivery, obstetrics, obstetric surgical procedures, obstetric labor complications, anal canal, episiotomy) and keywords (OASIS, obstetrical anal sphincter injury, anal injury, anal sphincter, vaginal delivery, suture, fecal incontinence, anal incontinence, overlap repair, end-to-end repair, bladder protocol, analgesia). Results were restricted to systematic reviews, meta-analyses, randomized controlled trials/controlled clinical trials, observational studies, and clinical practice guidelines. Results were limited to English- or French-language materials. Evidence was supplemented with references from the 2015 Society of Obstetricians and Gynaecologists of Canada guideline no. 330.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional recommendations).

INTENDED AUDIENCE

Obstetrical care providers.

TWEETABLE ABSTRACT

Updated Canadian guideline on recognition, prevention and management of obstetrical anal sphincter injuries (OASIS).

SUMMARY STATEMENTS

RECOMMENDATIONS.

Prevention of obstetric anal sphincter injuries with perineal support and lateral episiotomy: A historical cohort study

INTRODUCTION

There are many risk factors for obstetric anal sphincter injury (OASIS) and the interaction between these risk factors is complex and understudied. The many observational studies that have shown a reduction of OASIS rates after implementation of perineal support have short follow-up time. We aimed to study the effect of integration of active perineal support and lateral episiotomy on OASIS rates over a 15-year period and to study interactions between risk factors known before delivery.

MATERIAL AND METHODS

We performed a historical cohort study over the periods 1999-2006 and 2007-2021 at Stavanger University Hospital, Norway. The main outcome was OASIS rates. Women without a previous cesarean section and a live singleton fetus in cephalic presentation at term were eligible. The department implemented in 2007 the Finnish concept of active perineal protection, which includes support of perineum, control of fetal expulsion, good communication with the mother and observation of perineal stretching. The practice of mediolateral episiotomy was replaced with lateral episiotomy when indicated. We analyzed the OASIS rates in groups with and without episiotomy stratified for delivery mode, fetal position at delivery and for parity, and adjusted for possible confounders (maternal age, gestational age, oxytocin augmentation and epidural analgesia).

RESULTS

We observed a long-lasting reduction in OASIS rates from 4.9% to 1.9% and an increase in episiotomy rates from 14.4% to 21.8%. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with instrumental vaginal deliveries and occiput anterior (OA) position; 3.4% vs 10.1% (OR 0.31; 95% CI: 0.24-0.40) and 6.1 vs 13.9% (OR 0.40; 95% CI: 0.19-0.82) in women with occiput posterior (OP) position. Lateral episiotomy was also associated with lower OASIS rates in nulliparous women with spontaneous deliveries and OA position; 2.1% vs 3.2% (OR 0.62; 95% CI: 0.49-0.80). The possible confounders had little confounding effects on the risk of OASIS in groups with and without episiotomy.

CONCLUSIONS

We observed a long-lasting reduction in OASIS rates after implementation of preventive procedures. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with an instrumental delivery. Special attention should be paid to deliveries with persistent OP position.

Parturition at term: induction, second and third stages of labor, and optimal management of life-threatening complications-hemorrhage, infection, and uterine rupture

Childbirth is a defining moment in anyone's life, and it occurs 140 million times per year. Largely a physiologic process, parturition does come with risks; one mother dies every two minutes. These deaths occur mostly among healthy women, and many are considered preventable. For each death, 20 to 30 mothers experience complications that compromise their short- and long-term health. The risk of birth extends to the newborn, and, in 2020, 2.4 million neonates died, 25% in the first day of life. Hence, intrapartum care is an important priority for society. The American Journal of Obstetrics & Gynecology has devoted two special Supplements in 2023 and 2024 to the clinical aspects of labor at term. This article describes the content of the Supplements and highlights new developments in the induction of labor (a comparison of methods, definition of failed induction, new pharmacologic agents), management of the second stage, the value of intrapartum sonography, new concepts on soft tissue dystocia, optimal care during the third stage, and common complications that account for maternal death, such as infection, hemorrhage, and uterine rupture. All articles are available to subscribers and non-subscribers and have supporting video content to enhance dissemination and improve intrapartum care. Our hope is that no mother suffers because of lack of information.

A pre-post implementation study of a care bundle to reduce perineal trauma in unassisted births conducted by midwives

PROBLEM

The perineal-bundle is a complex intervention widely implemented in Australian maternity care facilities.

BACKGROUND

Most bundle components have limited or conflicting evidence and the implementation required many midwives to change their usual practice for preventing perineal trauma.

AIM

To measure the effect of perineal bundle implementation on perineal injury for women having unassisted births with midwives.

METHODS

A retrospective pre-post implementation study design to determine rates of second degree, severe perineal trauma, and episiotomy. Women who had an unassisted, singleton, cephalic vaginal birth at term between two time periods: January 2011 - November 2017 and August 2018 - August 2020 with a midwife or midwifery student accoucheur. We conducted logistic regression on the primary outcomes to control for confounding variables.

FINDINGS

data from 20,155 births (pre-implementation) and 6273 (post-implementation) were analysed. After implementation, no significant difference in likelihood of severe perineal trauma was demonstrated (aOR 0.86, 95% CI 0.71-1.04, p = 0.124). Nulliparous women were more likely to receive an episiotomy (aOR 1.49 95% CI 1.31-1.70 p < 0.001) and multiparous women to suffer a second degree tear (aOR 1.18 95% CI 1.09-1.27 p < 0.001).

DISCUSSION

This study adds to the growing body of literature which suggests a number of bundle components are ineffective, and some potentially harmful. Why, and how, the bundle was introduced at scale without a research framework to test efficacy and safety is a key concern.

CONCLUSION

Suitably designed trials should be undertaken on all proposed individual or grouped perineal protection strategies prior to broad adoption.

The relationship between perineal trauma and postpartum psychological outcomes: a secondary analysis of a population-based survey

BACKGROUND

Perineal trauma, involving either naturally occurring tears or episiotomy, is common during childbirth but little is known about its psychological impact. This study aimed to determine the associations between childbirth related perineal trauma and psychological outcomes reported by women three months after giving birth and to explore factors that could mediate relationships between perineal trauma and maternal psychological outcomes.

METHODS

This study was a secondary analysis of data from a cross-sectional population-based survey of maternal and infant health. A total of 4,578 women responded to the survey, of which 3,307 had a vaginal birth and were eligible for inclusion into the analysis. Symptoms of depression, anxiety, and post-traumatic stress (PTS) symptoms were assessed using validated self- report measures. Physical symptoms were derived from a checklist and combined to produce a composite physical symptoms score. Regression models were fitted to explore the associations.

RESULTS

Nearly three quarters of women experienced some degree of perineal trauma. Women who experienced perineal trauma reported having more postnatal physical symptoms (adjusted proportional odds ratio 1.47, 95%CI 1.38 to 1.57, p-value < 0.001), were more likely to report PTS symptoms (adjusted OR 1.19, 95%CI 1.04 to 1.36, p-value 0.010), and there was strong evidence that each unit increase in the physical symptoms score was associated with between 38 and 90% increased adjusted odds of adverse psychological symptoms. There was no evidence of association between perineal trauma and satisfaction with postnatal care, although there was strong evidence that satisfaction with labour and birth was associated with 16% reduced adjusted odds of depression and 30% reduced adjusted odds of PTS symptoms.

CONCLUSIONS

Women who experienced perineal trauma were more likely to experience physical symptoms, and the more physical symptoms a woman experienced the more likely she was to report having postnatal depression, anxiety and PTS symptoms. There was some evidence of a direct association between perineal trauma and PTS symptoms but no evidence of a direct association between perineal trauma and depression or anxiety. Assessment and management of physical symptoms in the postnatal period may play an important role in reducing both physical and psychological postnatal morbidity.

Management of Third and Fourth-Degree Perineal Tears After Vaginal Birth. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/079, December 2020)

Purpose This guideline provides recommendations for the diagnosis, treatment and follow-up care of 3rd and 4th degree perineal tears which occur during vaginal birth. The aim is to improve the management of 3rd and 4th degree perineal tears and reduce the immediate and long-term damage. The guideline is intended for midwives, obstetricians and physicians involved in caring for high-grade perineal tears.

Methods A selective search of the literature was carried out. Consensus about the recommendations and statements was achieved as part of a structured process during a consensus conference with neutral moderation.

Recommendations After every vaginal birth, a careful inspection and/or palpation by the obstetrician and/or the midwife must be carried out to exclude a 3rd or 4th degree perineal tear. Vaginal and anorectal palpation is essential to assess the extent of birth trauma. The surgical team must also include a specialist physician with the appropriate expertise (preferably an obstetrician or a gynecologist or a specialist for coloproctology) who must be on call. In exceptional cases, treatment may also be delayed for up to 12 hours postpartum to ensure that a specialist is available to treat the individual layers affected by trauma. As neither the end-to-end technique nor the overlapping technique have been found to offer better results for the management of tears of the external anal sphincter, the surgeon must use the method with which he/she is most familiar. Creation of a bowel stoma during primary management of a perineal tear is not indicated. Daily cleaning of the area under running water is recommended, particularly after bowel movements. Cleaning may be carried out either by rinsing or alternate cold and warm water douches. Therapy should also include the postoperative use of laxatives over a period of at least 2 weeks. The patient must be informed about the impact of the injury on subsequent births as well as the possibility of anal incontinence.

French guidelines for restrictive episiotomy during instrumental delivery were not followed by an increase in obstetric anal sphincter injury

The objective was to assess the influence of the French guidelines in favor of a restrictive use of episiotomy on both episiotomy and obstetric anal sphincter injury (OASI) rates during instrumental delivery. It was aulticenter study involving 193 maternities between 2000 and 2016. We included women with a singleton pregnancy, with cephalic presentation at 34 weeks of gestation or more who underwent an instrumental delivery. The study period was divided into three phases: 2000-2005 (reference) 2006-2011, and 2012-2016. We calculated the adjusted relative risk (aRR) of episiotomy and OASI and investigated for changes in episiotomy and OASI rates over time by using Prais-Winsten regression. We considered 96,035 deliveries. The episiotomy's risk was lower in 2006-2011 (69.4%) and 2012-2016 (59.1%) compared to 2000-2005 (81.2%), respectively: aRR 0.93 [0.92-0.95] and 0.89 [0.87-0.90]. The OASI's risk was higher in 2006-2011 (2.5%) and 2012-2016 (3.1%) compared to 2000-2005, respectively: aRR 1.30 [1.10-1.53]) and 1.57 [1.33-1.85]. However, Prais-Winsten regression showed no difference in the OASI rate during the study period. We observed a massive decrease in episiotomy use and a moderate increase in crude OASI's rate but multivariate analysis failed to report an association between these outcomes.

Modifiable and non-modifiable risk factors for obstetric anal sphincter injury in a Norwegian Region: a case-control study

Background

Obstetric anal sphincter injury (OASI) is a common and severe complication of vaginal delivery and may have short- and long-term consequences, including anal incontinence, sexual dysfunction and reduced quality of life. The rate of OASI varies substantially between studies and national birth statistics, and a recent meta-analysis concluded that there is a need to identify unrecognized risk factors. Our aim was therefore to explore both potential modifiable and non-modifiable risk factors for OASI.

Methods

We performed a case–control study in a single center maternity clinic in South-Eastern Norway. Data were extracted retrospectively from an institutional birth registry. The main outcome measure was the occurrence of the woman’s first-time 3^rd or 4^th degree perineal lesion (OASI) following singleton vaginal birth after 30 weeks’ gestation. For each woman with OASI the first subsequent vaginal singleton delivery matched for parity was elected as control. The study population included 421 women with OASI and 421 matched controls who gave birth during 1990–2002. Potential risk factors for OASI were assessed by conditional logistic regression analyses.

Results

The mean incidence of OASI was 3.4% of vaginal deliveries, but it increased from 1.9% to 5.8% during the study period. In the final multivariate regression model, higher maternal age and birthweight for primiparous women, and higher birthweight for the multiparous women, were the only non-modifiable variables associated with OASI. Amniotomy was the strongest modifiable risk factor for OASI in both primi- (odds ratio [OR] 4.84; 95% confidence interval [CI] 2.60–9.02) and multiparous (OR 3.76; 95% CI 1.45–9.76) women, followed by augmentation with oxytocin (primiparous: OR 1.63; 95% CI 1.08–2.46, multiparous: OR 3.70; 95% CI 1.79–7.67). Vacuum extraction and forceps delivery were only significant risk factors in primiparous women (vacuum: OR 1.91; 95% CI 1.03–3.57, forceps: OR 2.37; 95% CI 1.14–4.92), and episiotomy in multiparous women (OR 2.64; 95% CI 1.36–5.14).

Conclusions

Amniotomy may be an unrecognized independent modifiable risk factor for OASI and should be further investigated for its potential role in preventive strategies.

Classification and evaluation of episiotomy practices from 2004 to 2020 and association with OASIS

OBJECTIVE

To apply a new classification based on 7 clinically relevant subgroups to accurately describe episiotomy practices and evaluate the association between episiotomy and obstetrical anal sphincter injuries (OASIS) rates according to the classification's subgroups.

METHODS

Observational retrospective cohort study based on a population comprising 39487 women from 01/01/2004 to 31/12/2020 in a level III university maternity unit. The primary outcome was the overall episiotomy rate in the institution, its trend over the time as well as in each subgroup of obstetric population classification. Secondary outcome was the rate of OASIS third and fourth degree, its association with episiotomy practice.

RESULTS

The episiotomy rate decreased significantly from 43,2% to 20% in the total population. The overall OASIS rate was 0,34%, it remained significantly the same during the study period, although the association between OASIS and episiotomy was significant only in group 2 (Nulliparous with instrumental delivery) with a decrease of OASIS rate if using episiotomy (OR 0.5; 95% CI[0,3-0,8]).

CONCLUSION

The episiotomy rate can be decreased without exposing women to an increased risk of OASIS. It encourages restrictive practice of episiotomy, but episiotomy should be considered in case of nulliparous women with instrumental delivery.

Attitudes and knowledge regarding episiotomy use and technique in vacuum extraction: A web-based survey among doctors in Sweden

OBJECTIVES

Correct episiotomy use and technique may prevent obstetric anal sphincter injuries. We aimed to explore the attitudes, use, and technique regarding episiotomy among doctors in Sweden, and their willingness to contribute to a randomized controlled trial of lateral episiotomy or no episiotomy in vacuum extraction in nulliparous women.

STUDY DESIGN

A web-based survey was sent to members of the Swedish Society of Obstetrics and Gynecology (n = 2140). The survey included 31 questions addressing personal characteristics, use of episiotomy, a two-dimensional picture on which the respondents drew an episiotomy, and questions regarding attitudes towards episiotomy and participation in a randomized controlled trial. We calculated the proportion of supposedly protective episiotomies (fulfilling criteria of a lateral or mediolateral episiotomy and a length ≥ 30 mm). We compared the results between obstetricians, gynecologists, and residents using Chi-square and Kruskal-Wallis tests for differences between groups, and logistic regression to estimate the odds ratio (OR) of drawing a protective episiotomy.

RESULTS

We received 432 responses. Doctors without a vacuum delivery in the past year were excluded, leaving 384 respondents for further analyses. In all, 222 (57.8%) doctors reported use of episiotomy in<50% of vacuum extractions. We obtained 308 illustrated episiotomies with a median angle of 53°, incision point distance from the midline of 21 mm, and length of 36 mm, corresponding to a lateral episiotomy. Few doctors combined these parameters correctly resulting in 167 (54.2%) incorrectly drawn episiotomies. Residents drew shorter episiotomies than obstetricians and gynecologists. Doctors ranked episiotomy the least important intervention to prevent obstetric anal sphincter injuries in vacuum extraction. Doctors contributing to an ongoing randomized controlled trial of lateral episiotomy or no episiotomy in vacuum extraction were more able to draw a protective episiotomy (OR 3.69, 95% confidence interval 1.94-7.02).

CONCLUSIONS

Doctors in Sweden reported restrictive use of episiotomy in vacuum extraction and depicted lateral type episiotomies, although the majority were incorrectly drawn. Preventive episiotomy was ranked of low importance. Our results imply a need for education, training, and guidelines to increase uptake of correct episiotomy technique, which could result in improved prevention of obstetric anal sphincter injuries.

European guidelines on perinatal care- Peripartum care Episiotomy

OF RECOMMENDATIONS1. Episiotomy should be performed by indication only, and not routinely (Moderate quality evidence +++-; Strong recommendation). Accepted indications for episiotomy are to shorten the second stage of labor when there is suspected fetal hypoxia (Low quality evidence ++-; Weak recommendation); to prevent obstetric anal sphincter injury in vaginal operative deliveries, or when obstetric sphincter injury occurred in previous deliveries (Moderate quality evidence +++-; Strong recommendation)2. Mediolateral or lateral episiotomy technique should be used (Moderate quality evidence +++-; Strong recommendation). Labor ward staff should be offered regular training in correct episiotomy techniques (Moderate quality evidence +++-; Strong recommendation).3. Pain relief needs to be considered before episiotomy is performed, and epidural analgesia may be insufficient. The perineal skin needs to be tested for pain before an episiotomy is performed, even when an epidural is in place. Local anesthetics or pudendal block need to be considered as isolated or additional pain relief methods (Low quality evidence ++-; Strong recommendation).4. After childbirth the perineum should be carefully inspected, and the anal sphincter palpated to identify possible injury (Moderate quality evidence +++-; Strong recommendation). Primary suturing immediately after childbirth should be offered and a continuous suturing technique should be used when repairing an uncomplicated episiotomy (High quality evidence ++++; Strong recommendation).

Which elements were significant in reducing obstetric anal sphincter injury? A prospective follow-up study

Background

To examine which elements of an obstetric anal sphincter injury (OASI) care bundle were protective for OASI. Several interventional trials showed that application of a care bundle involving a hands-on approach to perineal protection may reduce the risk of OASI. Previously, we found that only the element “hand on the fetal head” in itself was protective, although the risk of a type 2 error was calculated to be 50%.

Methods

A prospective follow-up study in an obstetric department in Denmark with 3200 deliveries per year. We included a cohort of 10,383 women giving birth vaginally from gestational week 22 + 0 from 2016 through 2019. We documented on a person-level the five elements of the care bundle together with maternal and obstetrical characteristics. The elements were 1) communication, 2) visible perineum, 3) hand on fetal head, 4) perineal support and 5) certification. Regression analysis was used for analysis of associations. The primary outcome measure was OASI.

Results

The total rate of OASI in vaginally delivering women was 1.9%. The incidence was 3.2% in nulliparous women giving birth vaginally. The rate of cesarean section was 16.5% and for episiotomy 2.4%. The reduction in the incidence of OASI was sustained since 2013. Hand on the fetal head and perineal support both were protective factors for OASI. In case of a nulliparous woman with a neonate weighing 3500 g giving birth spontaneously, the relative risk (RR) for OASI was 0.50 (95% CI 0.49- 0.51) with use of hand on the fetal head together with perineal support against no use. Similarly, with a nulliparous woman giving birth to a neonate of 3500 g by vacuum extraction, the RR for OASI was 0.65 (95% CI 0.62-0.68) against no use.

Conclusions

Both hand on the fetal head and perineal support were associated with a reduced risk of OASI.

Prospective assessment of vacuum deliveries from midpelvic station in a tertiary care university hospital: Frequency, failure rates, labor characteristics and maternal and neonatal complications

BACKGROUND

Midpelvic vacuum extractions are controversial due to reports of increased risk of maternal and perinatal morbidity and high failure rates. Prospective studies of attempted midpelvic vacuum outcomes are scarce. Our main aims were to assess frequency, failure rates, labor characteristics, maternal and neonatal complications of attempted midpelvic vacuum deliveries, and to compare labor characteristics and complications between successful and failed midpelvic vacuum deliveries.

STUDY DESIGN

Clinical data were obtained prospectively from all attempted vacuum deliveries (n = 891) over a one-year period with a total of 6903 births (overall cesarean section rate 18.2% (n = 1258). Student's t-test, Mann-Whitney U-test or Chi-square test for group differences were used as appropriate. Odds ratios and 95% confidence intervals are given as indicated. The uni- and multivariable analysis were conducted both as a complete case analysis and with a multiple imputation approach. A p-value of <0.05 was considered statistically significant.

RESULTS

Attempted vacuum extractions from midpelvic station constituted 36.7% (n = 319) of all attempted vacuum extractions (12.9% (n = 891) of all births). Of these 319 midpelvic vacuum extractions, 11.3% (n = 36) failed and final delivery mode was cesarean section in 86.1% (n = 31) and forceps in the remaining 13.9% (n = 5). Successful completion of midpelvic vacuum by 3 pulls or fewer was achieved in 67.1%. There were 3.9% third-degree and no fourth-degree perineal tears. Cup detachments were associated with a significantly increased failure rate (adjusted OR 6.13, 95% CI 2.41-15.56, p< 0.001).

CONCLUSION

In our study, attempted midpelvic vacuum deliveries had relatively low failure rate, the majority was successfully completed within three pulls and they proved safe to perform as reflected by a low rate of third-degree perineal tears. We provide data for nuanced counseling of women on vacuum extraction as a second stage delivery option in comparable obstetric management settings with relatively high vacuum delivery rates and low cesarean section rates.

Obstetric anal sphincter injury by maternal origin and length of residence: a nationwide cohort study

OBJECTIVE

To estimate the association between maternal origin and obstetric anal sphincter injury (OASI), and assess if associations differed by length of residence.

DESIGN

Population-based cohort study.

SETTING

The Medical Birth Registry of Norway.

POPULATION

Primiparous women with vaginal livebirth of a singleton cephalic fetus between 2008 and 2017 (n = 188 658).

METHODS

Multivariable logistic regression models estimated adjusted odds ratios (aORs) for OASI with 95% CI by maternal region of origin and birthplace. We stratified models on length of residence and paternal birthplace.

MAIN OUTCOME MEASURES

OASI.

RESULTS

Overall, 6373 cases of OASI were identified (3.4% of total cohort). Women from South Asia were most likely to experience OASI (6.2%; aOR 2.24, 95% CI 1.87-2.69), followed by those from Southeast Asia, East Asia & the Pacific (5.7%; 1.59, 1.37-1.83) and Sub-Saharan Africa (5.2%; 1.85, 1.55-2.20), compared with women originating from Norway. Among women born in the same region, those with short length of residence in Norway (0-4 years), showed the highest odds of OASI. Migrant women across most regions of origin had the lowest risk of OASI if they had a Norwegian partner.

CONCLUSIONS

Primiparous women from Asian regions and Sub-Saharan Africa had up to two-fold risk of OASI, compared with women originating from Norway. Migrants with short residence and those with a foreign-born partner had higher risk of OASI, implying that some of the risk differential is due to sociocultural factors. Some migrants, especially new arrivals, may benefit from special attention during labour to reduce morbidity and achieve equitable outcomes.

TWEETABLE ABSTRACT

Anal sphincter injury during birth is more common among Asian and Sub-Saharan migrants and particularly among recent arrivals.

Women's experiences of the OASI Care Bundle; a package of care to reduce severe perineal trauma

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injury (OASI) is a severe form of perineal trauma that can occur during vaginal birth. Long-term morbidities include anal incontinence and psychosocial disorders. To reduce these injuries within England, Scotland and Wales, the OASI Care Bundle was introduced to 16 maternity units (January 2017-March 2018). The OASI Care Bundle comprises four elements: (1) antenatal information, (2) manual perineal protection, (3) medio-lateral episiotomy (when indicated) and 4) recognition and diagnosis of tears. As part of the project evaluation, a qualitative study was conducted to explore women's experiences of the OASI Care Bundle.

METHODS

Semi-structured interviews were conducted with women (n = 19) who received the OASI Care Bundle as part of their maternity care. This was to explore their experience of each element. A thematic analysis of the interview data was performed.

RESULTS

Three themes were identified: (1) memories of touch, whereby women reported that a 'hands-on' approach to perineal protection was a positive experience; (2) midwife as a supportive guide, where women reported that good communication facilitated a calm birth and post-birth diagnosis; (3) education: women need more information about perineal trauma.

CONCLUSION

This study contributes to the literature through its exploration of women's experiences of perineal protection techniques and diagnosis of perineal trauma. Interviewed women indicated that they did not experience any of the care bundle elements as an intrusion of their physical integrity. Additionally, an urgent need was identified for more information about perineal trauma in terms of risk, prevention and recovery.

Identifying the factors that influence midwives' perineal practice at the time of birth in the United Kingdom

OBJECTIVE

The Obstetric Anal Sphincter Injuries (OASI) Care Bundle is designed to reduce the incidence of obstetric anal sphincter injuries. However, introducing behavioural change requires an understanding of current practice. This study aims to establish midwives practise at the time of birth, and the factors that influence this.

DESIGN

Quantitative research - a national online survey.

SETTING

Nationwide - United Kingdom (UK). Participants 563 midwives from across the UK.

METHODS

An online survey of midwives' practice. Midwives were invited to participate through the Supervisor of Midwives network. Consent was sought on the landing page. Data analysis using descriptive and inferential statistics, with sub group analyses were used to explore variations in practice. Measurements Number of midwives using "hands on" the perineum and the influences on midwives' perineal practice at the time of birth.

FINDINGS

Most midwives preferred to use "hands on" the perineum at the time of birth (61.4%). "Hands on" practise was significantly associated with where midwives worked (p<0.001), risk factors for OASI (p<0.001), and the approach that they were taught in their midwifery training (p<0.01). Midwives expressed lack of confidence in some areas with a third unsure that they could identify the third degree tear category b (38.2%) or c (34.3%).

KEY CONCLUSIONS

There has been a growth in the number of midwives using "hands on" at the time of birth but midwives feel that they require additional training in regards to identifying an OASI. The study should be repeated following the roll out of the OASI care bundle, to identify its impact on midwives' perineal practice.

IMPLICATIONS FOR PRACTICE

The study identified that there needs to be an improvement in the recognition of OASI by midwives, and in future repeating the study would identify whether the OASI care bundle has influenced midwives' practice.

The OASI care bundle quality improvement project: lessons learned and future direction

Rising rates of obstetric anal sphincter injury (OASI) led to a collaborative effort by the Royal College of Obstetricians and Gynaecologists (RCOG) and the Royal College of Midwives (RCM) to develop and evaluate the OASI Care Bundle (OASI-CB). The OASI-CB comprises four practices (antenatal discussion about OASI, manual perineal protection, mediolateral episiotomy at 60° from the midline, and systematic examination of the perineum, vagina and ano-rectum after vaginal birth) and was initially implemented as part of a quality improvement (QI) project—“OASI1”—in 16 maternity units across Great Britain. Evaluation of the OASI1 project found that the care bundle reduced OASI rates and identified several barriers and enablers to implementation. This paper summarises the key findings, including strengths, limitations and lessons learned from the OASI1 QI project, and provides rationale for further evaluation of the OASI-CB.

Enhancing the identification of anal incontinence in women of reproductive age

Anal incontinence is an unpredictable and debilitating condition that can significantly reduce quality of life. Symptoms include the involuntary loss of solid and/or liquid stool, flatus incontinence and rectal urgency. Pregnancy and childbirth are two major factors that increase the risk of anal incontinence in women of reproductive age. Women at high risk of anal incontinence include those with a known history of the condition and those who have experienced severe perineal trauma, particularly after injury to the anal sphincters (third-degree and fourth-degree tears). Routine screening for anal incontinence of women in high-risk groups during pregnancy and after childbirth appears to be limited in clinical practice. This article discusses the potential benefits of screening for anal incontinence, outlines the factors that inhibit and enable screening, describes current bowel screening tools and their limitations, and explores how the identification of anal incontinence in women of reproductive age could be improved.

Changing paradigm of sacral neuromodulation and external anal sphincter repair for faecal incontinence in specialist centres

AIM

The aim of this study was to determine whether the paradigm of surgical intervention for faecal incontinence (FI) has changed between 2000 and 2013.

METHOD

This was a multi-centre retrospective study of patients who had undergone either sacral neuromodulation (SNM) or delayed sphincter repair or sphincteroplasty (SR) as a primary surgical intervention for FI in five centres in Europe and one in the United States. The flow of patients according to the intervention, sustainability of the treatment at a minimum follow-up of 5 years, complications and requirement for further interventions were recorded.

RESULTS

A total of 461 patients (median age 56 years, range 24-90 years, 41 men) had either SNM or SR as an index operation during the study period [SNM 284 (61.6%), SR 177 (38.4%)]. Among SNM patients, there were 169 revisional operations (change of battery and/or lead, re-siting or removal). At the time of last follow-up 203 patients (71.4%) continued to use SNM. Among SR patients, 30 (16.9%) had complications, most notably wound infection (22, 12.4%). During follow-up 32 patients (18.1%) crossed over to SNM. Comparing two 4-year periods (2000-2003 and 2007-2010), the proportion of patients operated on who had a circumferential sphincter defect of less than 90° was 48 (68%) and 45 (46%), respectively (P = 0.03), while those who had SNM as the primary intervention increased from 29% to 89% (P < 0.05).

CONCLUSION

The paradigm of surgical intervention for FI has changed with increasing use of SNM.

Evaluation of midwifery pelvic floor education and Training across the UK and Spain

OBJECTIVES

The aim of this study was to evaluate current education and training of student and registered midwives across the UK and Spain; analysing both pelvic floor teaching and practical experience.

STUDY DESIGN

A cross-sectional survey was carried out by 711 student and 384 registered midwives across different universities and regions in the UK and Spain.

RESULTS

The vast majority (91.5 % n = 382) of UK students complete training without ever cutting or repairing an episiotomy. This compares to 39.4 % (n = 85) of registered midwives who did not cut an episiotomy during training. Only 20 % (n = 9) of Spanish and 10 % (n = 45) of UK registered midwives felt confident undertaking these techniques. In Spain just 15 % (n = 6) of students, compared to 54.8 % (n = 80) of registered midwives had received teaching on longer-term pelvic floor complications.

CONCLUSION

There is a considerable deficit in the current training practices for midwives regarding episiotomies. This lack of practice and confidence may be impacting on the increased rates of perineal tears and pelvic dysfunction in post-partum women. Across registered midwives there are gaps in education regarding longer-term pelvic floor complications. Our study was limited by a smaller sample size from Spain compared to the UK. Our results show practical assessment of skills during training is desirable and could improve both the confidence and competence of midwives upon registration.

Risk factors for obstetric anal sphincter injury among parous women

PURPOSE

Nulliparity and operative vaginal delivery are established risk factor for obstetric anal sphincter injury (OASI). However, risk factors for OASIS occurrence among parous women delivering vaginally are not well-established. We aimed to study the risk factors for OASI occurrence among parous women.

METHODS

A retrospective study including all parous women who delivered vaginally at term during 2011-2019 at a university hospital. Deliveries of parous women with OASI were compared to deliveries without OASI. The risk factors associated with OASI were investigated.

RESULTS

Overall, 35,397 women were included in the study with an OASI rate of 0.4% (n = 144). A higher rate of only one previous vaginal delivery was noted in the OASI group (78.5% vs. 46.4%, OR [95% CI] 4.20, 2.82-6.25, p < 0.001). The rate of vacuum-assisted deliveries was comparable between the study groups. The median birth weight was higher among the OASI group (3566 vs. 3300 g, p < 0.001), as was the rate of macrosomic neonates (19.4% vs. 5.5%, OR [95% CI] 4.15, 2.74-6.29, p < 0.001). On multivariate logistic regression analysis, only two factors were independently positively associated with the occurrence of OASI: a history of only one previous vaginal delivery (adjusted OR [95% CI] 4.34, 2.90-6.49, p = 0.001), and neonatal birth-weight (for each 500 g increment) (adjusted OR [95% CI] 2.51, 1.84-3.44, p < 0.001).

CONCLUSIONS

Among parous women, the only factors found to be independently positively associated with OASI were the order of parity and neonatal birth-weight. Vacuum-assisted delivery was not associated with an increased risk of OASI among parous women.

The Incidence of and Predictors for Severe Perineal Trauma and Intact Perineum in Women Having a Waterbirth in England: A Hospital-Based Study

Background: To determine the incidence of and predictors for obstetric anal sphincter injuries (OASIS) and intact perineum in women giving birth in the water and compare with the general obstetric population. Materials and Methods: Data were retrospectively collected for women who had singleton cephalic presentation vaginal births in the water and the general obstetric population between August 2007 and December 2017. Results: We identified 1,007 women who had a waterbirth and 36,924 women from the general obstetric population. There was no significant difference in the incidence of OASIS between waterbirths and the general obstetric population (2.3% vs. 2.0%). Having a waterbirth was associated with a lower probability for an intact perineum (odds ratio [OR] = 0.83; confidence interval [95% CI]: 0.73-0.94) when compared with the general obstetric population (44.7% vs. 51.3%). Nulliparous women with a waterbirth when compared with multiparous women had an eightfold higher likelihood for the occurrence of OASIS (OR = 8.28; 95% CI: 2.64-25.86). The risk for a higher degree of OASIS was associated with increased maternal age in the total sample (OR = 1.08; 95% CI: 1.06-1.11) and with a lower body mass index (BMI) at booking in multiparous women (OR = 0.96; 95% CI: 0.92-0.99). The risk for any type of perineal trauma was associated with increased maternal age in the total sample (OR = 1.10; 95% CI: 1.07-1.13) and with a lower BMI at booking in multiparous women (OR = 0.95; 95% CI: 0.91-0.99). Conclusions: We found that giving birth in the water reduced the chance of having an intact perineum. We have also shown that nulliparity, increased maternal age in all women, and a lower BMI at booking in multiparous were associated with OASIS and lower rates of intact perineum in waterbirths.

Exploring clinicians' perspectives on the 'Obstetric Anal Sphincter Injury Care Bundle' national quality improvement programme: a qualitative study

INTRODUCTION

Obstetric anal sphincter injuries (OASI) can have severe debilitating consequences to women and health systems. The OASI Care Bundle quality improvement programme was introduced in 16 maternity units across England, Scotland and Wales (January 2017 to March 2018) to address increasing OASI rates.

OBJECTIVES

To explore clinicians' (midwives' and obstetricians') perspectives of the OASI Care Bundle with respect to (1) acceptability, (2) feasibility, and (3) sustainability.

DESIGN

A qualitative exploratory study using focus groups methodology.

SETTING

A total of 16 focus groups were conducted in 16 maternity units in England, Scotland and Wales where the OASI Care Bundle was implemented. Focus groups took place approximately 3 months following initial implementation of the care bundle in each unit.

PARTICIPANTS

A total of 101 clinicians participated, with an average of six per focus group. Participants volunteered to take part and compromised of 37 obstetricians and 64 midwives (including eight students). The majority were female and the mean age was 36.5 years.

RESULTS

Four main themes emerged: 'Implementation strategies', 'Opportunities to use the OASI Care Bundle', 'Does current practice need to change?' and 'Perceptions of what women want'. Midwives were more likely than obstetricians to report themes alluding to 'what women want' and variations in intrapartum perineal protection techniques. Both professional groups reported similar views of other themes, in particular regarding the supporting clinical evidence. Gaps were identified in clinicians' knowledge and experience of intrapartum perineal management.

CONCLUSIONS

Adoption of the OASI Care Bundle was associated with a number of cognitive and interpersonal factors, such as personal values, interprofessional working and how the intervention was launched; which both facilitated and impeded adoption. The 'what women want' theme has implications for maternal autonomy and needs further exploration. Our findings can be used by similar initiatives to reduce perineal trauma both nationally and internationally.

TRIAL REGISTRATION NUMBER

ISCTRN 12143325; https://doi.org/10.1186/ISRCTN12143325.

Impact of a quality improvement project to reduce the rate of obstetric anal sphincter injury: a multicentre study with a stepped-wedge design

Objective

To evaluate the impact of a care bundle (antenatal information to women, manual perineal protection and mediolateral episiotomy when indicated) on obstetric anal sphincter injury (OASI) rates.

Design

Multicentre stepped‐wedge cluster design.

Setting

Sixteen maternity units located in four regions across England, Scotland and Wales.

Population

Women with singleton live births between October 2016 and March 2018.

Methods

Stepwise region by region roll‐out every 3 months starting January 2017. The four maternity units in a region started at the same time. Multi‐level logistic regression was used to estimate the impact of the care bundle, adjusting for time trend and case‐mix factors (age, ethnicity, body mass index, parity, birthweight and mode of birth).

Main outcome measures

Obstetric anal sphincter injury in singleton live vaginal births.

Results

A total of 55 060 singleton live vaginal births were included (79% spontaneous and 21% operative). Median maternal age was 30 years (interquartile range 26–34 years) and 46% of women were primiparous. The OASI rate decreased from 3.3% before to 3.0% after care bundle implementation (adjusted odds ratio 0.80, 95% CI 0.65–0.98, P = 0.03). There was no evidence that the effect of the care bundle differed according to parity (P = 0.77) or mode of birth (P = 0.31). There were no significant changes in caesarean section (P = 0.19) or episiotomy rates (P = 0.16) during the study period.

Conclusions

The implementation of this care bundle reduced OASI rates without affecting caesarean section rates or episiotomy use. These findings demonstrate its potential for reducing perineal trauma during childbirth.

Tweetable abstract

OASI Care Bundle reduced severe perineal tear rates without affecting caesarean section rates or episiotomy use.

OASI Care Bundle reduced severe perineal tear rates without affecting caesarean section rates or episiotomy use.

Birth tears after spontaneous and vacuum-assisted births with different vacuum cup systems - a retrospective cohort study

Objectives Birth tears are a common complication of vaginal childbirth. We aimed to evaluate the outcomes of birth tears first by comparing the mode of vaginal birth (VB) and then comparing different vacuum cups in instrumental VBs in order to better advise childbearing women and obstetrical professionals. Methods In a retrospective cohort study, we analyzed nulliparous and multiparous women with a singleton pregnancy in vertex presentation at ≥37 + 0 gestational weeks who gave birth vaginally at our tertiary care center between 06/2012 and 12/2016. We compared the distribution of tear types in spontaneous births (SBs) vs. vacuum-assisted VBs. We then compared the tear distribution in the vacuum group when using the Kiwi Omnicup or Bird's anterior metal cup. Outcome parameters were the incidence and distribution of the different tear types dependent on the mode of delivery and type of vacuum cup. Results A total of 4549 SBs and 907 VBs were analyzed. Birth tear distribution differed significantly between the birth modes. In 15.2% of women with an SB an episiotomy was performed vs. 58.5% in women with a VB. Any kind of perineal tear was seen in 45.7% after SB and in 32.7% after VB. High-grade obstetric anal sphincter injuries (OASIS) appeared in 1.1% after SB and in 3.1% after VB. No significant changes in tear distribution were found between the two different VB modes. Conclusions There were more episiotomies, vaginal tears and OASIS after VB than after SB. In contrast, there were more low-grade perineal and labial tears after SB. No significant differences were found between different vacuum cup systems, just a slight trend toward different tear patterns.

Evaluation of a policy of restrictive episiotomy on the incidence of perineal tears among women with spontaneous vaginal delivery: A ten-year retrospective study

INTRODUCTION

Routine episiotomy is no longer recommended to limit obstetrical anal sphincter injuries (OASIs). We aimed to evaluate the effect of a restrictive policy of episiotomy on the risk of OASIs during spontaneous vaginal deliveries.

MATERIAL AND METHODS

We performed a retrospective single-center observational study among women with a term singleton cephalic fetus, with spontaneous vaginal delivery. The occurrence of episiotomy, intact perineum, first, second, third or fourth-degree (OASIs) perineal tears were compared before (period A, from 01/01/2006 to 12/31/2008) and after (period B, from 01/01/2012 to 12/31/2016) implementation of the restrictive policy. Odds of perineal tear were estimated using multivariable logistic regression models, stratified by parity.

RESULTS

From 2006-2016, the rate of episiotomy decreased, from 14.9 % (n/N=200/1141) to 4.7 % (94/1912). In period B (N=8984) vs A (N=8984), the rates of episiotomy were, 12.9 vs 26.6 % for nulliparas (p<0.01) and 2.3 vs 6.8 % for multiparas (p<0.01). Odds of OASIs were not different in period B vs A, both for nulliparas (0.9 vs 0.8 %, AOR=0.88(0.38-2.05)) and multiparas (0.4 vs 0.2 %, AOR=2.28(0.63-8.29). Odds of second-degree tear were higher in period B vs A, both for nulliparas (39.8 vs 17.4 %, AOR=2.55(2.11-3.08) and multiparas (26.2 vs 12.8 %, AOR=2.26(1.95-2.66)); and odds of intact perineum were lower (for nulliparas, 15.8 vs 24.9 %, AOR=0.61(0.42-0.90) and for multiparas, 47.1 vs 56.0 %, AOR=0.61(0.49-0.76)). No difference was observed for first-degree tears.

CONCLUSION

The progressive implementation of a restrictive policy of episiotomy during spontaneous vaginal delivery was not associated with an increased risk of OASIs over a ten-year period.

The impact of epidural analgesia on the mode of delivery in nulliparous women that attain the second stage of labor

Objective: We aimed to evaluate the impact of epidural analgesia on the mode of delivery of nulliparous women with a term single fetus in vertex presentation (NTSV) that attained the second stage of labor.Study design: A single-center retrospective study provided a strict and constant department protocol for epidural analgesia practice and obstetric interventions, between 2005 and 2014. Epidural users were compared to nonusers. The primary outcome was the mode of delivery. Secondary outcomes were diagnosis of prolonged second stage of labor and maternal and neonatal morbidities. The outcomes were evaluated by adjusted multivariate analyses (Adjusted Odds Ratios (aOR), 95% CI).Results: During the study period, 25,643 NTSV attained the second stage of labor; 18 676 (73%) epidural users and 6967 (27%) nonusers. Epidural users had an increased risk of instrumental delivery 2.48, [2.22-2.76], along with a lower risk of cesarean delivery 0.38, [0.29-0.50]. Notably, the diagnosis of prolonged second stage of labor was comparable among the study groups 0.99, [0.89-1.12]. The epidural users had a significantly higher risk of early postpartum hemorrhage 1.15, [1.04-1.27]. The risk for neonatal morbidity was comparable among the study groups 1.21 [0.90-1.63].Conclusion: Epidural analgesia in a population of NTSV that attains the second stage of labor is associated with a higher risk of instrumental delivery, nonetheless with a reduced risk of cesarean delivery; independent of the length of the second stage of labor is and safe for the neonate.

Metrics of perineal support (MOPS) study

BACKGROUND

Manual perineal protection (MPP) is an intrapartum intervention suggested to protect perineal integrity during childbirth. Proper execution of MPP is complex and evaluation of its true contribution is difficult in the clinical setting because of the large number of obstetric variables, some of which are hardly quantifiable. In this study we aimed to gather initial data on the forces executed by the accoucheur's thumb, index and middle fingers during MPP at the time of fetal head expulsion, quantify the duration of the intervention and investigate the timely interaction of the different components of MPP.

METHODS

Two bespoke right-handed measurement gloves (MG), with built in sensors, were designed and produced. The MG allowed the electronic real-time measurement of applied forces during MPP and transferred this data wirelessly to an integrated computer system. Sterile gloves were worn over the MG when used at the time of birth. The study was undertaken between January and December 2019. Singleton, term pregnant women having their first vaginal birth who provided a valid written consent were enrolled into this prospective pilot study. All deliveries were undertaken by one of two obstetricians experienced in MPP.

RESULTS

Twenty women were enrolled. The mean duration of execution of MPP during the last contraction was 13.6 s. In 20% it lasted < 5 s. The overall mean values of the average and maximum forces of the thumb, index and middle fingers were 26.7 N; 25.5 N; 20.2 N and 34.3 N; 32.6 N; and 27.6 N respectively. The onset of fingers and thumb activity was simultaneous in 13 cases (65%), while in seven (35%) deliveries the middle finger's force activity was initiated later.

CONCLUSIONS

MPP during fetal head expulsion happens over a short period of time. In the majority of cases the thumb and fingers actions started simultaneously. There were differences in the duration of application and the forces executed by the fingers and thumb between the two practitioners, however this was only significant for thumb measurements. The results obtained will aid in improving further MPP modeling studies to optimize the technique.

'Please Squeeze': A novel approach to perineal guarding at the time of delivery reduced rates of obstetric anal sphincter injury in an Australian tertiary hospital

BACKGROUND

Over the last decade the incidence of obstetric anal sphincter injuries (OASIS) has been steadily increasing locally and internationally. Investigations into reducing rates, and the long-term complications, of OASIS are required.

AIMS

To determine if applying a new method of perineal guarding at the time of delivery reduces the incidence of OASIS at an Australian tertiary hospital.

MATERIALS AND METHODS

A retrospective audit was performed for the three  years prior to and following mandatory introduction of a new method of perineal guarding. The novel 'Please Squeeze' technique involved placement of the accoucheur's thumb and index finger just above the line of the posterior fourchette at crowning and bringing them firmly one centimetre postero-medially to reduce tension. Demographic data were extracted from the unit's obstetric database (ObstetriX).

RESULTS

There were 9453 deliveries prior to, and 9805 deliveries following commencement of 'Please Squeeze', with no difference in the incidence of caesarean (30.4% vs 30.3% P = 0.87) or forceps (6.3% vs 5.8% P = 0.14) between groups. The incidence of primiparas (P = 0.005), ventouse (P < 0.001) and spontaneous vaginal deliveries (SVD) (P = 0.005) between groups. There was a clinically important 20% reduction in the incidence of OASIS across all vaginal deliveries from 3.5% to 2.8% (P = 0.006). In SVD, there was a 20% decrease in OASIS from 2.4% to 2.2% (P = 0.02), and a 14% decrease in OASIS with assisted vaginal delivery from 8% to 7.3% (P = 0.002). The incidence of episiotomy increased 16% (P < 0.001).

CONCLUSIONS

The novel 'Please Squeeze' perineal guarding method contributed to a reduced incidence of OASIS in an Australian tertiary hospital.

Are women attending a midwifery-led birthing center at increased risk of anal sphincter injury?

INTRODUCTION AND HYPOTHESIS

In recent years there has been renewed interest in midwifery-led care for women, with studies reporting similar neonatal outcomes despite lower rates of intervention in midwifery-led birthing centers. Research into obstetric anal sphincter injuries (OASI) in these birthing centers is scarce. The objective of this study was to compare the rate of OASI after spontaneous vaginal delivery in nulliparous women in consultant or midwifery-led units over a ten-year period.

METHODS

All spontaneous vaginal deliveries in nulliparous women from 2008 to 2017 were analyzed in a single-center retrospective study. Women who had neuraxial analgesia were excluded. The primary endpoint was OASI. Labor characteristics in both groups were compared, and a multiple regression model was created.

RESULTS

During the study period, there were 3260 spontaneous vaginal deliveries in nulliparous women; 75.7% (2467/3260) delivered in the consultant-led unit and 24.3% (793/3260) in the midwifery-led unit (MLU). Women delivering in the MLU had a greater risk of anal sphincter injury than those delivering in the CLU (4.9% [39/793] vs 2.5% [62/2467], OR 2.01, 95% CI 1.32 - 3.01). Significant risk factors that increased the risk of OASI on regression analysis were birthweight and delivery in the midwifery-led unit.

CONCLUSIONS

Women delivering in the midwifery-led unit appear to be at double the risk of OASI when compared to those delivering in the consultant-led unit. These results are in contrast to previous studies in midwifery-led centers. This difference may be site-specific and further research is required before these results form part of patient counseling.

What is the total impact of an obstetric anal sphincter injury? An Australian retrospective study

Introduction

Most data on obstetric anal sphincter injury (OASI) reflect short-term (< 12 months) or much longer term (> 10 years) impact. This study aimed to collate the extent of medium-term symptomology (1–6 years) and observe the effect on future birth choices to evaluate the cumulative impact of OASI in affected women.

Methods

A retrospective cohort of women affected by OASI completed a questionnaire covering bowel symptomology, sexual function, life impact and future birth choices. A custom-created adverse composite outcome for OASI incorporating effects on daily life, flatal/fecal incontinence and sexual function (OASIACO) was used as a threshold score to identify women with high levels of symptoms.

Results

Of 265 eligible and contactable women, 210 questionnaires were received (response rate 79%) at a mean of 4 years post-OASI. More than half (54%) experienced an OASIACO. A forceps birth (p = 0.03) or more severe grade of tear (p = 0.03) was predictive of OASIACO. One hundred one women had further children, with 48% reporting their delivery choices were impacted, 32% electing a cesarean delivery and 26% shifting to private care. Eighty women (40%) had not given birth again, and 29 (36%) of these indicated their OASI influenced this decision.

Conclusions

The total impact of an OASI on women affected is substantial. More than half experience ongoing symptoms and close to half report an impact on their future birth choices. It follows there would be a consequential load on the healthcare sector, and improved management and prevention programs should be implemented.

Electronic supplementary material

The online version of this article (10.1007/s00192-019-04108-3) contains supplementary material, which is available to authorized users.

Incidence and risk factors for obstetric anal sphincter ruptures, OASIS, following the introduction of preventive interventions. A retrospective cohort study from a Norwegian hospital 2012-2017

OBJECTIVE

A decrease of obstetric anal sphincter injuries (OASIS) was observed after preventive interventions were implemented at a Norwegian university hospital. The aim was to investigate whether the improvement had sustained over the following years.

MATERIALS AND METHODS

We performed a retrospective cohort study of 18 258 singleton vaginal cephalic births, ≥37 + 0 weeks of gestation during 2012-2017, examining data from the hospital's birth journals and separate registration forms. Interventions to prevent OASIS were implemented in 2011, and training in practical skills was repeated each year.

MAIN OUTCOME MEASURES

The main outcome was OASIS (n = 377).

RESULTS

Frequency of OASIS overall decreased from 3.6% prior to 2011 to 2.1% after the intervention and sustained at that level throughout the study period. A trend of fewer OASIS among spontaneous deliveries, decreasing from 2.1% to 1.2% (p = 0.01) was observed, but no trend was seen for instrumental deliveries (p = 0.37), where the incidence fluctuated between 4.0% and 9.3% with an average of 6.5%. Primiparity, increased maternal age and increased fetal head circumference were associated with more OASIS in spontaneous deliveries. In instrumental deliveries, primiparity, occiput posterior position and increased fetal head circumference were associated with more OASIS, whilst episiotomy was associated with fewer OASIS.

CONCLUSION

The incidence of obstetric anal sphincter injuries maintained at a similar level of around 2.1% during the six following years after introducing preventive interventions. Regularly repetition and practical training seemed to be effective.

Impact of animated instruction on tablets and hands-on training in applying bimanual perineal support on episiotomy rates: an intervention study

INTRODUCTION AND HYPOTHESIS

In Palestine, episiotomy is frequently used among primiparous women.This study assesses the effect of training birth attendants in applying bimanual perineal support during delivery by either animated instruction on tablets or hands-on training on episiotomy rates among primiparous women.

METHODS

An interventional cohort study was performed from 15 October 2015 to 31 January 2017, including all primiparous women with singletons and noninstrumental vaginal deliveries at six Palestinian hospitals. Intervention 1 (animated instructions on tablets) was conducted in Hospitals 1, 2, 3, and 4. Intervention 2 (bedside hands-on training) was applied in Hospitals 1 and 2 only. Hospitals 5 and 6 did not receive interventions. Differences in episiotomy rates in intervention and nonintervention hospitals were assessed before and after the interventions and presented as p values using chi-square test, and odds ratios (OR) with 95% confidence intervals (CI). Differences in the demographic and obstetric characteristics were presented as p values using the Kruskal-Wallis test.

RESULTS

Of 46,709 women, 12,841 were included. The overall episiotomy rate in the intervention hospitals did not change significantly after intervention 1, from 63.1 to 62.1% (OR = 0.96, 95% CI 0.84-1.08), but did so after intervention 2, from 61.1 to 38.1% (OR = 0.39, 95% CI 0.33-0.47). Rates after Intervention 2 changed from 65.0 to 47.3% (OR = 0.52, 95% CI 0.40-0.67) in Hospital 1 and from 39.4 to 25.1% (OR = 0.49, 95% CI 0.35-0.68) in Hospital 2.

CONCLUSIONS

Hands-on training of bimanual perineal support during delivery of primiparous women was significantly more effective in reducing episiotomy rates than animated instruction videos alone.

Severe perineal trauma among women undergoing vaginal birth after cesarean delivery: A population-based cohort study

BACKGROUND

To examine risk of severe perineal trauma among nulliparous women and those undergoing vaginal birth after cesarean delivery (VBAC).

METHODS

This is a population-based cohort study of all births to women with their two first consecutive singleton pregnancies in Stockholm-Gotland Sweden between 2008 and 2014. Risk of severe perineal trauma was compared between nulliparous women and those undergoing VBAC with severe perineal trauma being the main outcome measure. Associations between indication and timing of primary cesarean delivery and risk of severe perineal trauma in subsequent vaginal birth were analyzed using Poisson regression analysis.

RESULTS

The rate of severe perineal trauma among nulliparous women and those undergoing VBAC was 7.0% and 12.3%, respectively. Compared with nulliparous women, those undergoing VBAC were significantly older, had a shorter stature, and gave birth in a non-upright position to heavier infants with larger head circumferences. The rate of instrumental vaginal delivery among nulliparous women and those undergoing VBAC was 19.3% and 20.2%, respectively (P = 0.331). An increased risk of severe perineal trauma remained after adjustments among those undergoing VBAC (adjusted risk ratio 1.42, 95% CI 1.23-1.63). Level of risk was not associated with indication (dystocia or signs of fetal distress) of primary cesarean delivery, nor how far the woman had progressed in labor (fully dilated versus planned cesarean delivery) before delivering by cesarean.

CONCLUSIONS

Compared with nulliparous women, those undergoing VBAC are at increased risk of severe perineal trauma, irrespective of indication and timing of primary cesarean delivery.

Effects of an intervention program for reducing severe perineal trauma during the second stage of labor

BACKGROUND

Obstetric anal sphincter injuries lead frequently to short- and long-term consequences for the mother, including perineal pain, genital prolapse, and sexual problems. The aim of the study was to evaluate whether the implementation of an intervention program in the second stage of labor involving altered perineal support techniques reduced severe perineal trauma.

METHODS

All women reaching the second stage of labor and giving birth vaginally to singleton babies at Landspítali University Hospital (comprising 76% of births in Iceland in 2013) were enrolled in a cohort study. Data were recorded retrospectively for 2008-2010 and prospectively in 2012-2014, for a total of 16 336 births. During 2011, an intervention program was implemented, involving all midwives and obstetricians working in the labor wards. Two professionals assessed and agreed on classification of every perineal tear.

RESULTS

The prevalence of obstetric anal sphincter injuries decreased from 5.9% to 3.7% after the implementation (P < 0.001). Third-degree tears decreased by 40%, and fourth-degree tears decreased by 56% (P < 0.001). The prevalence of first-degree tears increased from 25.8% to 33.1%, whereas second-degree tears decreased from 44.7% to 36.6% between the before and after study periods. Severe perineal trauma was linked to birthweight, and this did not change despite the new intervention.

CONCLUSIONS

Active intervention to reduce perineal trauma was associated with an overall significant decrease in obstetric anal sphincter injuries. Good perineal visualization, manual perineal support, and controlled delivery of the fetal head were essential components for reducing perineal trauma.

Coaching a slow birth with the woman in an empowered position may be less harmful than routine hands-on practice to protect against severe tears in birth - A discussion paper

BACKGROUND

Different hands-on interventions to protect women from severe perineal tears after birth have been widely implemented. Evidence to support the routine use of hands-on interventions to reduce severe tears is mainly based on aggregated data from observational studies.

AIM

To critically discuss the current evidence for the implementation of hands-on intervention as a routine practice to protect women from severe tears after birth.

DISCUSSION

Observational studies have been used to justify the routine use of hands-on intervention to protect women from severe perineal tears despite randomized controlled trials and systematic reviews showing lack of benefit. There is strong evidence supporting the slow speed at the time of birth to prevent severe perineal tears. While hands-on intervention does reduce the speed of birth, it may have a negative effect on the birth process, on neonatal outcomes and women's agency.

CONCLUSION

Evidence-based practice requires sufficient evaluation of interventions before being implemented in clinical practice as well as valuing the level of evidence when making clinical decisions. Evaluation of hands-on interventions to protect women from severe perineal tears must include not just one outcome of interest, but also an assessment of how the intervention interferes with the normal mechanism of birth, and how it affects neonatal outcomes and the autonomy of women.

Effect of team training and monitoring on the rate of failed mid and low cavity vacuum extraction: a hospital based intervention study

BACKGROUND

Clinical team training has been advocated as a means to improve delivery care, and failed extractions is a suggested variable for clinical audit in instrumental vaginal delivery. Other activities may also have intended or unintended effects on care processes or outcomes.

METHODS

We retrospectively observed 1074 mid and low vacuum extraction deliveries during three time periods (prevalence periods): Baseline (period 0), implemented team training (period 1 and 2) and monitoring of traction force during vacuum extraction (period 2). Our primary outcome was failed extraction followed by emergency cesarean section or obstetric forceps delivery.

RESULTS

The prevalence proportion (relative risk) of failed extraction decreased significantly after implementation of team training, from 19% (period 0) to 8 % (period 1), corresponding to a relative risk of 0.48 [0.26-0.87]. The secondary procedural outcome complicated delivery (duration > 15 min or number of pulls > 6, or cup detachment > 1) was decreased in period 2 compared to period 1, RR 0.42 [0.23-0.76]. Secondary clinical (neonatal) outcome were not affected.

CONCLUSION

Clinically based educational efforts and increased monitoring improved procedural outcome without improving neonatal outcome. The study design has inherent limitations in making causal inference.

Does water birth affect the risk of obstetric anal sphincter injury? Development of a prognostic model

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injury (OASI) is a significant complication of vaginal delivery. Water birth has become a popular preference for women giving birth in the UK, however, there is limited data on the risk of OASI following water birth. Our aim was to assess OASI risk in low-risk women giving birth in water without medical intervention compared with on land and to create a prognostic model for OASI prediction.

METHODS

This was a retrospective study of 15,734 low-risk women giving birth by spontaneous vaginal delivery between January 2008 and October 2014 in a midwifery-led unit (MLU). Patient factors and delivery data were analysed to identify differences between water and land births. Univariate analysis determined factors that statistically predicted OASI and was then used to create multivariate analysis. Significant multivariate factors were used to create a prognostic model to predict likelihood of OASI.

RESULTS

OASI rates were 1.6% on land and 3.3% in water [odds ratio (OR) 2.10, 95% confidence interval (CI) 1.5-2.94). Multivariate analysis confirmed water birth, ethnicity and parity as independent risk factors for OASI (adjusted OR water birth: 1.77 (CI 1.25-2.51). Our prognostic model showed Black and Asian primigravidae following water birth had the highest risk of OASI and white multiparae on land the lowest.

CONCLUSION

This study of comparable low-risk women shows an increased risk of OASI following water birth compared with land birth. Use of this prognostic model will help women determine their risk of OASI following birth in water or on land.