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

INTRODUCTION AND HYPOTHESIS: 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).

METHODS

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).

RESULTS

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).

CONCLUSIONS

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.