Learning from Obstetric Anal Sphincter Injury claims within the NHS in England: A thematic review (NHS Resolution, 12 December 2025)

Summary

This report, produced by NHS Resolution in collaboration with the Royal College of Obstetricians and Gynaecologists, analyses Obstetric Anal Sphincter Injuries (OASI) claims made by claimants between 2011/12 and 2021/22. It highlights common themes in OASI claims and provides guidance to help healthcare professionals prevent OASI where possible. It also identifies key areas of care that can be improved, ensuring better support for women affected by OASI.

Content

This report identifies the following areas for improvement in the prevention, diagnosis, and management of OASI:

• Safer assisted vaginal births – Ensure all obstetricians are trained on the basic principles of assisted instrumental delivery, including avoidance of excessive force so that gentle traction is applied with a uterine contraction and appropriate use of ventouse and forceps with episiotomy when required. This should also include how to assess for OASIs.
• Supervision of trainee clinicians – Provide adequate support and supervision of both midwives and non-consultant grade doctors when performing complex deliveries such as assisted births, particularly rotational deliveries. Promote and encourage perineal protection, especially during difficult deliveries.
• Diagnosis of OASI – Focus on appropriate clinical training to ensure clinicians can perform a systematic bimanual vaginal and rectal examination to identify an OASI. This should include using the pill rolling technique to identify OASI at the time of birth so that the injury can be repaired, as this gives the best outcomes.
• Education – Educate clinicians on the symptoms that can affect women who sustain OASIs, as well as the social, psychological, and economic impact of these injuries. This includes supporting clinical teams to consider underlying risk factors during pregnancy, follow the appropriate pathway of assessment, and escalate concerns about potential OASIs, supported by greater awareness of the significant impact these injuries can have on women. We must also ensure that clinicians are appropriately trained and supervised to repair OASIs.
• Awareness of rectovaginal fistula (an undetected or repaired fourth degree tear) – This remains a rare complication of OASIs but has a devastating impact on women. Clinicians should be aware of this potential complication, its presenting symptoms, and how to assess for this in a multidisciplinary context.
• Pathway for management of women with missed OASIs – Management remains very variable across units, depending on local facilities and expertise available, and further guidance is urgently needed to improve consistency and long-term outcomes.

NHS Resolution have also produced a one page poster that summarises the key messages at a glance which clinicians are encouraged to print and display this poster on notice boards within clinical areas. You can find this here.