Abstract :
Mediolateral episiotomy (MLE) is one of the most performed procedures on women worldwide. However, the protective effect of MLE against Obstetric Anal Sphincter InjurieS (OASIS) is conflicting. The aim of this study was to evaluate the relationship between MLE and OASIS in primiparous, using 2D transperineal ultrasound (TPUS) immediately after delivery to aid in the diagnosis of anal sphincter injuries. This randomized control trial was carried out in Ain Shams University Maternity Hospital labour ward, between October 2018 and October 2021, included 260 primiparous at 37 weeks of gestation or beyond, which were randomly assigned to either routine or no episiotomy groups and the types of perineal injuries were analysed 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. Routine MLE was associated with higher frequency of third-degree perineal tears (3.8% versus 1.7%); statistically significant. 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 MLE is advised. TPUS is a helpful tool in detection of OASIS immediately postpartum. A delivery practice change is required our local setting, through enhancing awareness, increasing structured training of junior staff, adherence to updated delivery protocols, and increased surveillance, which can lead to lower episiotomy rates with better outcomes.