The Effect of Mediolateral Episiotomy on Obstetric Anal Sphincter Injuries following Vaginal Delivery

Abstract

his study was a randomized controlled trial to evaluate the impact of Mediolateral episiotomy (MLE) on Obstetric Anal Sphincter InjurieS (OASIS) in primiparous ladies, using clinical examination as well as 2D transperineal ultrasound (TPUS) immediately postpartum to assess the anal sphincter complex integrity, carried out in the labour ward of Ain Shams University Maternity Hospital, between October 2018 and October 2021, where 260 primiparous at 37 weeks of gestation or beyond, presented in labour or required induction of labour, were included and randomly assigned to either routine or no episiotomy groups and the types of perineal injuries were analyzed following childbirth. The episiotomy rate was 100% in the routine group versus 6.9% in the no episiotomy group. The overall incidence of third-degree perineal tears in both groups was 3.46%, with no cases of fourth-degree tears in the studied population. The incidence of third-degree perineal tears in a per protocol analysis was 1.7% versus 3.8% in no episiotomy and routine episiotomy groups respectively, statistically significant (RR 0.43, 95% CI 0.08-2.17, p-value 0.026) To conclude, the routine use of MLE in primiparous was associated with higher incidence of third-degree perineal tears, and as anal sphincter injuries are known to have short- and long-term morbidities, therefore the restrictive use of M