Anal incontinence after vaginal delivery: a five-year prospective cohort study

The long-term prevalence of anal incontinence after vaginal delivery is unknown. The aim of the present study was to evaluate the prevalence of anal incontinence in primiparous women 5 years after their first delivery and to evaluate the influence of subsequent childbirth.

A total of 349 nulliparous women were prospectively followed up with questionnaires before pregnancy, at 5 and 9 months, and 5 years after delivery. A total of 242 women completed all questionnaires. Women with sphincter tear at their first delivery were compared with women without such injury. Risk factors for development of anal incontinence were also analyzed.

Anal incontinence increased significantly during the study period. Among women with sphincter tears, 44% reported anal incontinence at 9 months and 53% at 5 years (P = .002). Twenty-five percent of women without a sphincter tear reported anal incontinence at 9 months and 32% had symptoms at 5 years (P < .001). Risk factors for anal incontinence at 5 years were age (odds ratio [OR] 1.1; 95% confidence interval [CI] 1.0-1.2), sphincter tear (OR 2.3; 95% CI 1.1-5.0), and subsequent childbirth (OR 2.4; 95% CI 1.1-5.6). As a predictor of anal incontinence at 5 years after the first delivery, anal incontinence at both 5 months (OR 3.8; 95% CI 2.0-7.3) and 9 months (OR 4.3; 95% CI 2.2-8.2) was identified. Among women with symptoms, the majority had infrequent incontinence to flatus, whereas fecal incontinence was rare.

Anal incontinence among primiparous women increases over time and is affected by further childbirth. Anal incontinence at 9 months postpartum is an important predictor of persisting symptoms.