Conclusions

• More injuries to the anal sphincter can be detected and treated if an ultrasound examination is added to the routine visual and manual examinations currently performed on women immediately postnatally. Fewer women would therefore develop faecal incontinence and reductions to their quality of life.
• Fewer injuries to the anal sphincter are recorded when delivery ward staff are trained to promote slow delivery, to manually protect the perineal region with different handholds, and to use episiotomies when they are necessary. It is not possible to resolve which of these compon­ents are important.
• An episiotomy can prevent anal sphincter injuries when a woman, who is giving birth for the first time, requires vacuum extraction. However, the procedure itself causes a perineal injury. Even warm compresses applied to the perineum during the pushing stage of childbirth can provide some protection against anal sphincter injury. More research is needed to establish which examination methods can be routinely used directly postnatally to ensure that anal sphincter injuries do not go undetected. Rectal palpation after childbirth has not been assessed as a dia­gnostic method. Examination methods need to be simple as well as both accurate and sensitive. Unreliable methods for measuring outcomes and unclear diagnostic criteria make the existing research results difficult to assess.