Faecal incontinence 20 years after one birth: a comparison between vaginal delivery and caesarean section

The aetiology of bowel incontinence in middle-aged women is multifactorial and the contribution of birth-related factors later in life is still poorly defined. The aim was to assess prevalence, risk factors and severity of faecal (FI, defined as the involuntary loss of faeces-solid or liquid) and anal incontinence (AI, includes FI as well as the involuntary loss of flatus) 20 years after one vaginal (VD) or one caesarean section (CS).

This was a registry-based national cohort study of primiparae giving birth in 1985-1988 and having no further births (n = 5,236). Data from the Swedish Medical Birth Register were linked to information from a pelvic floor disorder questionnaire in 2008 (response rate 65.2%). Analysis of variance and multivariate analysis were used to obtain adjusted prevalence and odds ratios (adj-OR).

Overall prevalences of FI and AI were 13.6 and 47.0%. FI prevalence was higher after VD compared with CS [14.5 versus 10.6%, adj-OR 1.43, 95% confidence interval (CI) 1.16-1.77] but was not increased after acute versus elective CS. Perineal tear (≥second degree) increased the prevalence and risk of FI compared with no tear (22.8 versus 13.9%, adj-OR 1.95, 95% CI 1.33-2.85). The prevalence of FI was lower after VD with an episiotomy (11.1%) and similar to that after CS (10.6%). With each unit increase of current body mass index the odds of FI increased by 6% (OR 1.06, 95% CI 1.04-1.08).

Late FI and AI prevalences were higher after VD compared with CS. Perineal tear (≥second degree) versus no tear doubled the prevalence of FI. FI prevalence was similar after a CS and a VD combined with episiotomy.