Prevalence and risk factors for peri- and postpartum urinary incontinence in primiparous women in China: a prospective longitudinal study.

INTRODUCTION AND HYPOTHESIS: We sought to characterize risk factors of urinary incontinence (UI) during pregnancy and the postpartum period in primiparous women in China.
METHODS: We enrolled 10,098 women from the seven regions of China ≥28 weeks' gestation from September 2007 to May 2009 and administered the Bristol Female Lower Urinary Tract Symptoms questionnaire to estimate the presence of different types of UI during late pregnancy (37 to 42 weeks' gestation) and at 6 weeks and 6 months postpartum. We also collected details of pregnancy and childbirth and demographic data. McNemar's test, multinomial logistic regression models, and binary logistic regression models were used.
RESULTS: Multivariable analysis revealed six independent risk factors for SUI: age, more frequent exercise, alcohol consumption, higher body mass index, larger waist circumference, and history of constipation. For those with no UI in late pregnancy, 3.7% and 3.0% developed new cases at 6 weeks and 6 months postpartum, respectively. Risk factors for UI at 6 months were frequent exercise, rural residence, perineal laceration, and lateral episiotomy. Prevalence of all UI was 26.7% in late pregnancy, 9.5% at 6 weeks postpartum, and 6.8% at 6 months postpartum. Most cases were stress urinary incontinence (18.6%, 6.9%, and 5.0%, at the respectively times).
CONCLUSIONS: Rates of UI in primiparous women in China are consistent with those reported elsewhere. Rural location, frequent exercise, and birth-related injuries are risk factors for UI at 6 months postpartum.