Episiotomy: Have we got it right?

Background: A recent randomized controlled trial (Bergendahl et al, BMJ 2024) reported a 50% reduction in obstetric anal sphincter injury (OASI) in nulliparous patients undergoing vacuum delivery who were assigned to lateral episiotomy versus no episiotomy.

Objective: To evaluate OASI in singleton nulliparous vacuum deliveries at >= 34 weeks’ gestation in a US population.

Materials and Methods: 

Study design: Retrospective observational study.

Population: Singleton nulliparous vacuum deliveries at >= 34 weeks’ gestation at 17 US hospitals (2022-2023) participating in a perinatal quality improvement program (OB COAP)

Intervention: Midline (M)  or mediolateral  (ML) episiotomy versus no episiotomy (N).

Primary outcome: Incidence of 3rd or 4th degree laceration (Obstetrical anal sphincter injury or OASI). 

Secondary outcome: blood loss.

Statistical analysis: Unadjusted odds ratios (OR) for OASI were calculated for each ML and M group compared to the N group. Adjusted ORs controlled for diabetes (gestational and pre-pregnancy)  and birthweight. The Kruskal-Wallis test was used to compare blood loss.

 Results: 

915 vacuum deliveries were included. 148 (16.1%) had an episiotomy: 79 (53.4%) were midline and 69 (46.6%) were mediolateral.