Anal incontinence after vaginal delivery:: a prospective study in primiparous women

Objective To investigate the incidence and degree of anal incontinence after vaginal delivery among primiparous women and to define associated risk factors. Design Prospective observational study. Setting Karolinska Institutet, Danderyd Hospital, Sweden, a university hospital. Participants Three hundred and forty-nine primiparous women. Methods Questionnaires distributed within the first days after delivery and re-distributed five and nine months postpartum. Analysis of delivery records. Results Eighty percent of the women answered all questionnaires. At five months postpartum, 2% of the women had symptoms of faecal incontinence and 25% had symptoms of involuntary flatus. At nine months postpartum, 1% of the women had symptoms of faecal incontinence and 26% had symptoms of involuntary flatus. The majority of the women had infrequent symptoms and a decrease in severity was noted at nine months. Symptoms of incontinence were more common in women who sustained a sphincter tear at delivery. Risk factors for incontinence at five months included maternal age, duration of the second stage of labour, instrumental vaginal delivery, and clinically diagnosed sphincter tear at delivery. Development of incontinence at nine months was associated with maternal age and clinically diagnosed sphincter lear at delivery. Conclusions The present study demonstrates that infrequent involuntary flatus is a common symptom after vaginal delivery in primiparous women. These symptoms of involuntary flatus frequently improved and only a few women suffered from frank faecal incontinence. Factors associated with an increased risk of anal incontinence and sphincter tears should be considered during delivery.