Risks of anal incontinence from subsequent vaginal delivery after a complete obstetric anal sphincter tear

Abstract

Objective: To assess the influence of various risk factors on long term anal incontinence in women with a complete obstetric tear of the anal sphincter.

Design: Postal questionnaire.

Setting: Department of Gynecology and Obstetrics, Aarhus University Hospital, Denmark.

Subjects: 152 women with complete obstetric tear of the anal sphincter.

Main outcome measures: Occurrence and duration of anal incontinence in relation to any delivery.

Results: 56 of 121 respondents had experienced a subsequent vaginal delivery; 23 (41%) of these had had transient anorectal incontinence directly after the complete tear and four (7%) had permanent anorectal incontinence. In the 23 women with transient anorectal incontinence directly after the complete tear, 9 (39%; 95% CI 19%-59%) developed anorectal incontinence after the next delivery, and this was permanent in four (17.4%; 95% CI 2%-33%). In the 29 women without anorectal incontinence after complete tear, two had transient incontinence of flatus but for less than 14 days after the next delivery.

Conclusions: Transient anal incontinence after a complete tear is a predictor of anal incontinence after subsequent vaginal delivery. The major long term problem in our study of premenopausal women was incontinence of flatus. This possibility should be discussed with the women when a further pregnancy is planned.