[Fetal expulsion: Which interventions for perineal prevention? CNGOF Perineal Prevention and Protection in Obstetrics Guidelines]

Influence of in utero fetal death on perineal tears in vaginal deliveries

The aim of this work was to evaluate and compare the incidence of perineal tears and Obstetrical anal sphincter injuries (OASIS) after vaginal delivery following a in utero fetal death (IUFD) compared with those with a live-birth. We conducted a single-center, retrospective cohort study using a database of all women who underwent a spontaneous vaginal delivery in the level III maternity ward. Exclusion criteria were breech presentation, cesarean section birth, instrumental delivery, multiple pregnancy, delivery before 24 + 6 weeks of gestation (WG) and termination of pregnancy for medical reasons. Women from the database were divided into two groups: an "in utero fetal death" (IUFD) group and a control group. Women were included in the IUFD group if they had a spontaneous vaginal delivery following a fetal demise after 24 + 6 WG in cephalic presentation between January 2006 and June 2020. Women in the "control" group were selected from the same database and were included if they underwent a spontaneous vaginal delivery of a live fetus in cephalic presentation, after 24 + 6 WG, during the same period. Each woman in the "IUFD" group was matched to two women (ratio 1:2) in the control group for parity, maternal age, body mass index, gestation and birth weight. The primary outcome was the presence of a sutured or unsutured perineal tear. During the study period, 31,208 patients delivered at a level III maternity hospital. Among them, 215 and 430 women were included in the IUFD group and the control group respectively. The two groups were comparable for all demographic and clinical characteristics except for an epidural analgesia (92% versus 70% in the control group, p < 0.01) and labor induction (86% versus 17% in the control group, p < 0.01). The incidence of any perineal tears was 13% (28/15) in the IUFD group versus 16% (70/430) in the control group. Relative risk of any perineal tears was non significative (RR = 0.8 IC95% [0.5-1.2]). The incidence of first-degree perineal tears was 10% in the IUFD group and 11% in the control group. The incidence of second-degree perineal tears was 18% in the IUFD group and 28% in the control group. Relative risk of first-degree perineal tears (RR = 0.88 95% CI [0.5-1.4]) and second-degree tears (RR = 0.51 95% CI [0.2-1.4]) were non significative. No obstetrical anal sphincter injury was found in either group. Vaginal delivery following a fetal demise did not appear to be either a risk factor or a protective factor for perineal tears. But there as a trend toward a lower incidence of second degree perineal tears in this context.

Incidence of obstetric anal sphincter injuries following breech compared to cephalic vaginal births

INTRODUCTION

Obstetric anal sphincter injuries (OASIs) at the time of childbirth can lead to serious consequences including anal incontinence, dyspareunia, pain and rectovaginal fistula. These types of lesions and their incidence have been well studied after cephalic presentation deliveries, but no publications have specifically addressed this issue in the context of vaginal breech delivery. The goal of our study was to evaluate the incidence of OASIs following breech deliveries and compare it with cephalic presentation births.

METHODS

This was a retrospective cohort study involving 670 women. Of these, 224 and 446 had a vaginal birth of a fetus in the breech (breech group) and cephalic (cephalic group) presentations respectively. Both groups were matched for birthweight (± 200 g), date of delivery (± 2 years) and vaginal parity. Main outcome of interest was to evaluate the incidence of OASIs following breech vaginal birth compared to cephalic vaginal births. Secondary endpoints were the incidence of intact perineum or first-degree tear, second-degree perineal tear and rates of episiotomies in each group.

RESULTS

There was no statistically significant difference in OASIs incidence between the breech and cephalic groups (0.9% vs. 1.1%; RR 0.802 (0.157; 4.101); p = 0.31). There were more episiotomies in the breech group (12.5% vs. 5.4%, p = 0.0012) and the rate of intact or first-degree perineum was similar in both groups (74.1% vs. 75.3%, p = 0.7291). A sub-analysis excluding patients with episiotomy and history of OASIs did not show any statistically significant difference either.

CONCLUSION

We did not demonstrate a significant difference in the incidence of obstetric anal sphincter injuries between women who had a breech vaginal birth compared to cephalic.

Effectiveness of episiotomy to prevent OASIS in nulliparous women at term

OBJECTIVE

To assess the association between episiotomy and severe obstetric anal sphincter injury (OASIS) in nulliparous women at term according to the use of an instrument for delivery with control confounding by indication.

METHODS

This was an observational retrospective cohort study including 12 346 women from 2004 to 2020. All nulliparous women with a cephalic singleton pregnancy were included. The primary outcome was the occurrence of OASIS. Association between episiotomy and OASIS was assessed by multivariate logistic regression with adjustment for confounding factors and stratification on the use of an instrument at delivery. Propensity score matching was used to account for indication bias.

RESULTS

Among 12 346 women included, 7803 (63.2%) had an episiotomy and 4543 (36.8%) did not have an episiotomy; the rate of OASIS was similar in both groups (0.7%). After stratification on use of instrument, an association between episiotomy and OASIS was shown in the case of instrumental delivery (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.26-0.80) but not if the delivery was spontaneous (OR 0.76, 95% CI 0.29-1.98). The result was similar after matching on propensity score (in the case of operative vaginal delivery: OR 0.20, 95% CI 0.10-0.75).

CONCLUSION

Episiotomy seems to be a protective factor for OASIS in nulliparous woman at term only in the case of operative vaginal delivery.

Obstetrical anal sphincter injury and unnecessary episiotomy are both associated with anal incontinence 8 years after childbirth: A nationwide database analysis

OBJECTIVE

to assess the relationship between anal incontinence (AI) 8 years after childbirth and the occurrence of Obstetrical Anal Sphincter Injury (OASI) and/or performance of an episiotomy during childbirth.

METHODS

This is a nationwide database analysis performed on two national medico-administrative databases, including all the women aged ≥18 years who delivered infants in France in 2012. The main outcome measure was AI in the 8-years after delivery.

RESULTS

Of the 163,443 perineal tears reported, 0.47% were grade-3 and 0.08% were grade-4; 8,938 women experienced AI (1.33%) and 261 women experienced severe AI (0.04%). Episiotomies performed in the absence of risk factors for OASI were significantly associated with an increased risk of AI (Odds Ratio (OR)=1.59; 95% Confidence Interval (CI):1.49-1.69;p<0.001). Grade 3 and 4 OASI also significantly increased the risk of AI and severe AI. Mediolateral episiotomy was preventative of OASI when performed in subjects at risk (OR=0.26; 95% CI:0.23-0.30; p<0.001) but contributed to OASI in the absence of risk (OR=2.18; 95% CI:1.98-2.40; p<0.001).

CONCLUSIONS

OASI is a risk factor for AI. Episiotomies could reduce the occurrence of OASI, but they could also have a increase the risk of long-term AI in the absence of risk factors for OASI.

Impact of a selective use of episiotomy combined with Couder's maneuver for the perineal protection

PURPOSE

To evaluate the impact of a selective use of episiotomy combined with Couder's maneuver on the incidence of perineal tears in spontaneous term deliveries.

METHODS

A comparative, retrospective, mono-centric study in a university maternity unit was designed and included all primiparous women who delivered spontaneously after 37 weeks of gestation in cephalic presentation. Two cohorts were studied, before and after the practice of Couder's maneuver. In the first cohort, the ''OSE cohort'' only selective episiotomies were performed from January 2009 to December 2010. In the second cohort, from January 2016 to December 2017, the ''SEC cohort'' selective episiotomies combined with Couder's maneuver were performed by midwives and obstetricians. The primary outcome was the type of perineal tears, according to the Royal College of Obstetricians and Gynaecologists (RCOG) classification.

RESULTS

A total of 2081 patients were included: 909 patients in the OSE cohort and 1172 patients in the SEC cohort. Couder's maneuver was performed in 59% of the SEC cohort. In the SEC cohort, there were an increase in the number of intact perinea (55% versus 63%, p < 0.001), a decrease in second-degree perineal tears (18% versus 11%, p < 0.001) and a decrease in labia minora tears (48% versus 37%, p < 0.001). The rate of obstetrical anal sphincter injuries was less than 1% in both cohorts (0.3% versus 0.5%, p = 0.7).

CONCLUSION

A selective use of episiotomy combined with Couder's maneuver could reduce the incidence of perineal tears, particularly second-degree perineal tears, without increasing the rate of obstetrical anal sphincter injuries.

A novel classification for evaluating episiotomy practices: application to the Burgundy perinatal network

Background

Though the rate of episiotomy has decreased in France, the overall episiotomy rate was 20% in the 2016 national perinatal survey. We aimed to develop a classification to facilitate the analysis of episiotomy practices and to evaluate whether episiotomy is associated with a reduction in the rate of obstetric anal sphincter injuries (OASIS) for each subgroup.

Methods

This population-based study included all the deliveries that occurred in the Burgundy Perinatal Network from 2011 to 2016. The main outcome was episiotomy, which was identified thanks to the French Common Classification of Medical Procedures. An ascending hierarchical cluster analysis was performed to build the classification. A clinical audit using the classification was conducted yearly in all obstetric units. The episiotomy rates were described throughout the study period for each subgroup of the classification. The OASIS rates were evaluated by subgroup and the association between mediolateral episiotomy and OASIS was investigated for each subgroup.

Results

Our analyses included 81,290 pregnant women. The classification comprised 7 subgroups: ₍₁₎ nulliparous single cephalic at term, ₍₂₎ nulliparous single cephalic at term with instrumental delivery, ₍₃₎ multiparous single cephalic at term, ₍₄₎ multiparous single cephalic at term with instrumental delivery, ₍₅₎ all preterm deliveries (< 37 weeks gestation), ₍₆₎ all breech deliveries, ₍₇₎ all multiple deliveries.

Episiotomy rates ranged from 6.2% in Group 3 to 40.9% in Group 2. From 2011 to 2016, every group except breech deliveries experienced a significant decrease in episiotomy rates, ranging from − 28.1 to − 61.0%.

The prevalence of OASIS was the highest in Groups 2 (3.0%) and 4 (2.2%). Overall OASIS rates did not significantly differ with episiotomy use (P = 0.25). However, we found that the use of episiotomy was associated with a reduction in OASIS rates in Groups 1 and 2 (odds ratio 0.6 [95% CI 0.4–0.9] and 0.4 [0.3–0.5], respectively). This reduction was only observed in Group 4 with forceps delivery (odds ratio 0.4 [0.1–0.9]).

Conclusion

We developed the first classification for the evaluation of episiotomy practices based on 7 clinically relevant subgroups. This easy-to-use tool can help obstetricians and midwives improve their practices through self-assessment.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2424-2) contains supplementary material, which is available to authorized users.