Objective: To assess the long term impact of obstetric anal sphincter rupture on the frequency of anal and urinary incontinence and to identify factors to predict women at risk.
Design: An observational study.
Settings: Departments of Obstetrics and Gynaecology and of Surgery D, Glostrup County University Hospital, Denmark.
Participants: Ninety-four consecutive women who had sustained an obstetric anal sphincter rupture.
Interventions: Assessment of history, anal manometry, anal sphincter electromyography and pudendal nerve terminal motor latency at three months postpartum A questionnaire regarding anal and urinary incontinence was sent two to four years postpartum.
Main outcome measures: The frequency of anal and urinary incontinence and risk factors for the development of incontinence.
Results: Thirty of 72 women (42%) who responded had anal incontinence two to four years postpartum; 23 (32%) had urinary incontinence and 13 (18%) had both urinary and anal incontinence. Overall, 40 of 72 women (56%) had incontinence symptoms. The occurrence of anal incontinence was associated with pudendal nerve terminal motor latencies of more than 2.0 ms, and the occurrence of urinary incontinence was associated with the degree of rupture, the use of vacuum extraction and previous presence of urinary incontinence. Seventeen women had subsequently undergone a vaginal delivery in relation to which four (24%) had aggravation of anal incontinence, and three (18%) had aggravation of urinary incontinence. Of the women with incontinence, 38% wanted treatment but only a few had sought medical advice.
Conclusions: Obstetric anal sphincter rupture is associated with a risk of approximately 50% for developing either anal or urinary incontinence or both. The prediction of women at risk is difficult. Information and routine follow up of all women with obstetric anal sphincter rupture is mandatory.