Evolution and risk factors of anal incontinence during the first 6years after first delivery: a prospective cohort study.

Abstract

To explore changes in prevalence of anal incontinence (AI) from late first pregnancy to 6years postpartum, and to evaluate possible risk factors for changes in AI during the 6-year period. Prospective longitudinal cohort study. Two Norwegian health regions. Women with first deliveries between May 2009 and December 2010. Participants reported AI in late pregnancy, 6months, 1 and 6years after first delivery using postal or digital questionnaires. AI prevalence was calculated, and mixed effects Poisson regression analyses with robust variance were applied. AI from late pregnancy to 6years postpartum. Among 1571 participants, 65% had normal vaginal first deliveries, 20% had vaginal deliveries complicated by instrumental intervention and/or obstetric anal sphincter injury (IVD±OASIS). Nearly 1 in 10 women reported persistent incontinence during the 6years. The overall AI prevalence was reduced from late pregnancy to 1year postpartum for all modes of delivery. At 6years postpartum, women with IVD±OASIS had a higher AI prevalence (23%; 95% CI 16-30%) compared with women with caesarean section (8%; 95% CI 2-13%) or normal vaginal delivery (12%; 95% CI 9-16%). Moreover, women who were <23years, ≥34years, unemployed during first pregnancy, who had active bowel disease (PR: 2.4; 95% CI 2.0-2.7), or bowel evacuation problems during the 6-year period had higher AI prevalence. Mode of first delivery modified AI prevalence during the 6-year period, whereas age, bowel disease and bowel evacuation problems were associated with higher prevalence of AI from late first pregnancy to 6years postpartum. Complicated vaginal delivery, age and bowel emptying problems increase the risk of long-term anal incontinence.