Risk factors for urinary incontinence 1 year after the first vaginal delivery in a cohort of primiparous Danish women

The objective was to examine the relationship between maternal and perinatal factors and the occurrence of stress (SUI) or mixed (MUI) urinary incontinence (UI) 1 year after the first vaginal delivery in primiparous women.

Participants in this prospective cohort were recruited consecutively from June 2003 to July 2005 from all eligible women who delivered in the department. A validated questionnaire, the International Consultation of Incontinence Questionnaire Short Form (ICIQ-SF) was completed by all participants 2–3 days after delivery, and a similar second questionnaire was filled out 1 year later. Additional data were obtained from the medical records. The first questionnaire was completed by 1,018 women (63 %) and the second by 859 women (84 %). The study group comprised the 575 women without any UI before the pregnancy and who had a vaginal delivery. The primary analysis comprised 117 women with either SUI or MUI 1 year after the vaginal delivery and 403 women without any UI.

In univariate analyses, the following factors were associated with SUI or MUI: prepregnancy body mass index (BMI) ≥ 30 (p < 0.05), UI during the pregnancy (p < 0.05), perineal lesions (p < 0.05), and anal sphincter tears (p = 0.05). Logistic regression analysis showed that SUI or MUI was strongly associated with UI during the pregnancy [adjusted odds ratio (OR) 4.7, 95 % confidence interval (CI) 2.9–7.7) and inversely associated with oxytocin augmentation (adjusted OR 0.5, 95 % CI 0.3–0.9).

SUI or MUI 1 year after the first vaginal delivery was strongly associated with UI during the pregnancy and inversely associated with oxytocin augmentation.