The effect of mode of delivery, parity, and birth weight on risk of urinary incontinence.

To examine the relationship between symptoms of urinary incontinence (UI) and mode of delivery, parity, and birth weight, data were obtained from a population-based random sample of 3,205 black, Hispanic, and white women age 30-79 in the Boston Area Community Health Survey. Measures include UI symptoms [>or=3 (moderate/severe) Sandvik's severity index]; reproductive history [live birth(s), no live births, never pregnant]; mode of delivery for live births (>or=1 vaginal birth, cesarean delivery only); parity (1, 2, >or=3); and maximum birth weight of live births (<4,000 g, >or=4,000 g). Using logistic regression, women having >or=1 vaginal delivery had twice the odds of UI compared to women with no pregnancies (P = 0.002) or only cesarean deliveries (P = 0.032). There was no difference in odds of UI between cesarean delivery only and never pregnant, by parity or birth weight. Vaginal delivery contributes to risk of UI for black, Hispanic, and white women.