Specific obstetrical risk factors for urinary versus anal incontinence 4 years after first delivery

Delivery can be complicated by urinary or anal incontinence (UI or AI). We hypothesized that the mechanisms of injury may differ for UI and AI. Hence, obstetrical risk factors may be specific for different types of incontinence.

Data on maternal characteristics were collected at first delivery. Data on incontinence were obtained by a questionnaire completed by 627 women 4 years after first delivery. UI was defined by "Do you have involuntary loss of urine" and AI by "Do you have involuntary loss of flatus or stool". A multinomial logistic regression analysis was conducted to assess risk factors for UI only, AI only, and UI+AI.

Twenty-two percent of women reported UI only, 6.5% AI only, and 6.5% both. Risk factors associated with UI only were age (at first delivery)≥ 30 (OR 2.27 [95% CI 1.47-3.49]), pre-existing UI (6.44 [2.19-19.0]) and pregnancy UI (3.64 [2.25-5.91]). Risk factors associated with AI only were length of the second active stage> 20minutes (2.86 [1.15-7.13]) and third degree perineal tear (20.9 [1.73-252]). Significant predictors of UI+AI were age ≥ 30 (2.65 [1.29-5.46]), no epidural (4.29 [1.65-11.1]), third degree perineal tear (20.0 [1.28-314]), and UI before pregnancy (32.9 [9.00-120]). Cesarean delivery was not significantly associated with UI, AI, or UI+AI, although for all three outcomes, the adjusted odds ratios were substantially less than one.

We found specific associations between obstetrical risk factors and urinary versus anal incontinence 4 years after first delivery. Our results are consistent with the hypothesis that the underlying mechanisms of injury differ for UI and AI.