Croydon Health Services NHS Trust

A multi-centre quality improvement project to reduce incidence of obstetric anal sphincter injury (OASI)

As official support providers to the second Health Foundation’s scaling up improvement programme we provided advice to enable the phased implementation of a care bundle to reduce the incidence of obstetric anal sphincter injury (OASI) across 16 maternity units in England, Scotland and Wales.

The project was a collaboration between the Royal College of Obstetricians and Gynaecologists (RCOG), Croydon Health Services NHS Trust, the Royal College of Midwives (RCM) and the London School of Hygiene and Tropical Medicine (LSHTM).

An OASI is an injury to the anal sphincter muscle sustained during childbirth. This can result in medical complications including anal incontinence and psychological problems.

Over the past 10 years, OASI rates have risen by more than 4 per cent, to 5.9 per cent in the UK. Possible reasons for this include inconsistent training, skills and prevention, lack of awareness of risk factors and variation in practice amongst healthcare professionals.

This project tackled this by introducing a package of interventions including a care bundle and guide, a multidisciplinary skills development module for healthcare professionals and campaign materials to raise awareness. The project reduced overall OASI injury rates by increasing the use of standardised prevention practices.

Find out more about OASI at:


Find out more about the project