Risk of urinary incontinence symptoms in oral contraceptive users: a national cohort study from the Swedish Twin Register

ObjectiveTo assess the impact of oral contraceptives on lower urinary tract dysfunction in premenopausal women.DesignNationwide cohort study.SettingNational registry.Patient(s)A total of 10,791 women (born 1959–1985) from the population- based Swedish Twin Registry who participated in a web-based survey of common diseases.Intervention(s)None.Main Outcome Measure(s)Symptoms of urinary incontinence.Result(s)For users of oral contraception there was a significantly reduced risk for symptoms of stress urinary incontinence, mixed urinary incontinence, and urgency urinary incontinence. The reduction remained significant when adjusting for age, body mass index, and pregnancy history. A reduced prevalence of symptoms of overactive bladder in oral contraceptive users was also observed although the association was nonsignificant. There were no significant associations between lower urinary tract symptoms and women using a levonorgestrel-releasing intrauterine device compared with noncontraceptive users, with the exception of nocturia.Conclusion(s)Oral contraceptive use reduces the overall risk for symptoms of urinary incontinence.