Anal incontinence after vaginal delivery or cesarean section

Uncertainties remain as to whether a cesarean section is protective for the short-term and long-term development of anal incontinence. Our aim was to explore whether women who had delivered only vaginally were at greater risk of anal incontinence than nulliparous women and women who had undergone cesarean sections only.

Background information, medical history, and data on anal incontinence (defined as fecal or flatus incontinence weekly or more) reported by women participating in a large population-based health survey in Norway (the Nord-Trøndelag Health Study 3) during the period October 2006 to June 2008 were collected and linked to data from the Medical Birth Registry of Norway. The prevalence of anal incontinence was calculated and multivariate logistic regression analyses were applied.

The mean age of the 12 567 women was 49.9 years. The age and educational level of women who had cesarean sections only were similar to those who had a vaginal delivery and obstetric anal sphincter injuries (OASIS). Nulliparous women and those who had a vaginal delivery and no OASIS were older and had higher educational achievements than women who had delivered by cesarean section exclusively, and women with OASIS. One in four women with OASIS reported anal incontinence compared with one in six of the other women (P < .001). Age, educational level, diarrhea, constipation, birthweight, and OASIS increased the risk of anal incontinence in all women. Parity was associated with anal incontinence in parous women only. No differences were found for fecal urgency.

Women with vaginal deliveries complicated by OASIS are at increased risk of anal incontinence. However, no increased risk of anal incontinence was found in nulliparous women or women who had cesarean sections only or vaginal deliveries not complicated by OASIS.