Impact of a quality improvement project to reduce the rate of obstetric anal sphincter injury: a multicentre study with a stepped-wedge design

BJOG. 2021 Feb;128(3):584-592. doi: 10.1111/1471-0528.16396. Epub 2020 Aug 9.

Abstract

Objective: To evaluate the impact of a care bundle (antenatal information to women, manual perineal protection and mediolateral episiotomy when indicated) on obstetric anal sphincter injury (OASI) rates.

Design: Multicentre stepped-wedge cluster design.

Setting: Sixteen maternity units located in four regions across England, Scotland and Wales.

Population: Women with singleton live births between October 2016 and March 2018.

Methods: Stepwise region by region roll-out every 3 months starting January 2017. The four maternity units in a region started at the same time. Multi-level logistic regression was used to estimate the impact of the care bundle, adjusting for time trend and case-mix factors (age, ethnicity, body mass index, parity, birthweight and mode of birth).

Main outcome measures: Obstetric anal sphincter injury in singleton live vaginal births.

Results: A total of 55 060 singleton live vaginal births were included (79% spontaneous and 21% operative). Median maternal age was 30 years (interquartile range 26-34 years) and 46% of women were primiparous. The OASI rate decreased from 3.3% before to 3.0% after care bundle implementation (adjusted odds ratio 0.80, 95% CI 0.65-0.98, P = 0.03). There was no evidence that the effect of the care bundle differed according to parity (P = 0.77) or mode of birth (P = 0.31). There were no significant changes in caesarean section (P = 0.19) or episiotomy rates (P = 0.16) during the study period.

Conclusions: The implementation of this care bundle reduced OASI rates without affecting caesarean section rates or episiotomy use. These findings demonstrate its potential for reducing perineal trauma during childbirth.

Tweetable abstract: OASI Care Bundle reduced severe perineal tear rates without affecting caesarean section rates or episiotomy use.

Keywords: Obstetric anal sphincter injury; perineal tear; quality improvement.

Publication types

  • Evaluation Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anal Canal / injuries
  • Cesarean Section / adverse effects
  • Cesarean Section / standards
  • Cesarean Section / statistics & numerical data
  • Cluster Analysis
  • Delivery, Obstetric / adverse effects
  • Delivery, Obstetric / standards*
  • Delivery, Obstetric / statistics & numerical data
  • England / epidemiology
  • Episiotomy / adverse effects
  • Episiotomy / standards
  • Episiotomy / statistics & numerical data
  • Female
  • Humans
  • Lacerations / epidemiology*
  • Lacerations / prevention & control
  • Logistic Models
  • Obstetric Labor Complications / epidemiology*
  • Obstetric Labor Complications / prevention & control
  • Perineum / injuries
  • Pregnancy
  • Quality Improvement / statistics & numerical data*
  • Research Design
  • Risk Factors
  • Scotland / epidemiology
  • Wales / epidemiology