Implementation of the RCOG guidelines for prevention of obstetric anal sphincter injuries (OASIS) at two London Hospitals: A time series analysis

Objective: To audit the impact of implementation of the RCOG guidelines for prevention of Obstetric anal sphincter injuries (OASIS) by introducing antenatal perineal massage, manual perineal protection, and cutting episiotomies at 60° to the midline at the time of crowning.

Design: Time series analysis; Setting - Two London teaching hospitals; Royal Free London (RFL) and Barnet; Population or Sample - All nulliparous women undergoing vaginal birth; Methods - Training was provided for above techniques. EPISCISSORS-60 were introduced to perform 60° episiotomies. Data were extracted from maternity databases and dashboards; Main Outcome Measures - OASIS rates before and after implementation.

Results: Data from 2566 births were analysed. In operative vaginal deliveries (OVD), OASIS declined from 9.6% to 2% (p = 0.001) at Barnet and from 5.6% to 4.2% (p = 0.4) at RFL. OASIS reduced in nulliparous OVD's given episiotomies from 6.3% in the 'before' period to 0.6% in the 'after' period [p = 0.01] at Barnet. Before introduction of the EPISCISSORS-60, OASIS rate was 6.3% with episiotomies and 30% without episiotomies (p = 0.000). After introduction of the EPISCISSORS-60, OASIS rate was 0.63% with episiotomies v 16% without episiotomies (p = 0.000) at Barnet. At RFL, OASIS rate was 2.6% with episiotomies, and 42% without episiotomy (p = 0.000). In SVD's at Barnet, OASIS declined from 6.6% before to 0% after (p = 0.000) in women given episiotomies while it declined from 5.4% to 3% (p = 0.12) in those not given episiotomies. After introduction of the EPISCISSORS-60, OASIS was 0% in women with episiotomies and 3% in those without episiotomies (p = 0.04). In SVD's at RFL, OASIS was 0% in women given episiotomy v 4.7% without episiotomy (p = 0.03).

Conclusions: Deliveries with EPISCISSORS-60 episiotomies had lesser OASIS than those without episiotomies in both nulliparous OVD's and SVD's. OASIS was lower with EPISCISSORS-60 episiotomies than those with eyeballed episiotomies.