Effect of mode of delivery on the incidence of urinary incontinence in primiparous women

Objective: To estimate the effect of mode of delivery on the incidence of urinary incontinence in primiparous women. Methods: A population-based survey was mailed to all Oregon women who delivered a liveborn neonate in a 1-year period. Data were collected on urinary incontinence, childbirth experience, and other risk factors for incontinence at 3-6 months postpartum. Univariable analyses were conducted using t tests and Wilcoxon rank-sum tests for continuous variables and χ tests for categorical variables. Logistic regression analyses were used to estimate odds ratios and 95% confidence intervals for demographic and clinical risk factors. Results: A total of 15,787 women completed the survey, for a response rate of 39%. Of these women, 5,599 were primiparous, completed the survey in the desired timeframe, submitted information on their urinary continence, and did not have incontinence before pregnancy. A total of 955 (17.1%) reported leakage of urine. Women who had vaginal deliveries were more likely to have urinary incontinence than women who had cesarean deliveries (odds ratio 4.96 [95% confidence interval 3.82-6.44], P<.001). This risk increased with assisted delivery and perineal laceration. No statistical difference in the incidence of urinary incontinence was found among women who had elective cesarean deliveries (6.1%), women who had cesarean deliveries after laboring (5.7%), and women who had cesarean deliveries after laboring and pushing (6.4%). Conclusion: Urinary incontinence is common in the immediate postpartum period after a woman's first pregnancy. Although vaginal delivery increases the risk of urinary incontinence, labor and pushing alone without vaginal delivery do not appear to increase this risk significantly. Level of Evidence: II.