Mediolateral episiotomy and risk of obstetric anal sphincter injuries and adverse neonatal outcomes during operative vaginal delivery in nulliparous women: a propensity-score analysis

Abstract

Background The potential protective effect of mediolateral episiotomy for obstetrical anal sphincter injuries (OASIs) remains controversial during operative vaginal delivery because of the difficulties to take into account the risk factors and clinical conditions at delivery; in addition, little is known about the potential benefits of mediolateral episiotomy on neonatal outcomes. The objectives were to investigate the associations between mediolateral episiotomy and both OASIs and neonatal outcomes, using propensity scores. Methods We performed a retrospective population-based observational study from a perinatal registry that includes all births in a French region between 2010 and 2017. All nulliparous women with singleton pregnancy delivering by operative vaginal deliveries at 37 weeks gestational age or later were included. Inverse-probability-of-treatment weighting with propensity scores was used to minimize indication bias. OASIs was defined as third and fourth-degree tears according to Royal College of Obstetricians and Gynecologists. Two neonatal outcomes were studied: condition at birth (5-min Apgar score less than 7 and/or umbilical artery pH less than 7.10), and admission to neonatal intensive care unit. Results The study population consisted of 7589 women; 2880 (38.0%) received mediolateral episiotomy. After applying propensity scores, episiotomy was associated with a lower rate of OASIs in forceps/spatula delivery (2.3 vs 6.8%, Risk Ratio (RR) 0.38, 95% Confidence Interval (CI) 0.28–0.52) and in vacuum delivery (1.3 vs 3.4%, RR 0.27, 95% CI 0.20–0.38) as compared with no episiotomy. Mediolateral episiotomy was associated with better condition at birth in case of forceps/spatula delivery (4.5 vs 8.8%, RR 0.56, 95% CI 0.39–0.81). In cases of fetal distress (40.7%), mediolateral episiotomy was associated with better condition of infant at birth in women who delivered by forceps/spatula (4.2 vs 13.5%, RR 0.52, 95% CI 0.31–0.89). No association was found with neonatal unit admission (RR 0.93, 95% CI 0.50–1.74). Conclusions Use of mediolateral episiotomy was associated with a lower rate of OASIs during operative vaginal delivery, and in infants it was associated with better condition at birth following forceps/spatula delivery.

Episiotomy for Medical Indications during Vaginal Birth—Retrospective Analysis of Risk Factors Determining the Performance of This Procedure

“…According to the researchers, this can be explained by a higher frequency of operative deliveries [ 40 ]. In turn, Desplanches et al (2022) found that mediolateral episiotomy reduces the risk of obstetric anal sphincter injuries among nulliparous women that are undergoing operative vaginal delivery [ 41 ].…”

Evaluation of perineal wound healing and pain outcomes after low‐angle mediolateral episiotomy in women undergoing vaginal childbirth: A systematic review and meta‐analysis

“…Additionally, episiotomy is employed to facilitate the birthing process, particularly in cases of fetal distress or when there is a need for operative vaginal deliveries, such as with forceps or vacuum assistance. The practice of episiotomy, widely adopted in the mid‐20th century, was initially perceived as a preventative measure against more severe spontaneous tears and subsequent pelvic floor disorders 3 . However, its routine use has been questioned in recent decades, leading to a more judicious and individualised approach.…”

“…The practice of episiotomy, widely adopted in the mid‐20th century, was initially perceived as a preventative measure against more severe spontaneous tears and subsequent pelvic floor disorders. 3 However, its routine use has been questioned in recent decades, leading to a more judicious and individualised approach. Contemporary research emphasises the importance of evaluating maternal factors such as tissue elasticity, foetal size, and the progress of labour before deciding on an episiotomy.…”

Obstetric Interventions Among Native and Migrant Women: The (Over)use of Episiotomy in Portugal

“…Commonly reported indications for episiotomy include fetal distress, potentially complicated births (e.g., breech or shoulder dystocia), forceps or vacuum deliveries (in order to prevent obstetric anal sphincter injury), large babies, and preterm births [25][26][27][28]. However, these indications are based on tradition or clinical experience [29], with limited scientific evidence to support them [21,27], whereas the contribution of episiotomy to increased maternal morbidity is well established [20,26].…”