Urinary incontinence in nulliparous women and their parous sisters.

Objective: To investigate the role of vaginal delivery and familial factors in the development of urinary incontinence by comparing the prevalence of this condition in nulliparous women and their parous sisters.

Methods: A sample of 143 pairs of nulliparous/parous postmenopausal sisters completed a comprehensive questionnaire regarding symptoms of pelvic floor disorders. Of these, 101 pairs underwent clinical evaluation of urinary incontinence and genital prolapse.

Results: Among this sample of biological sisters, urinary incontinence was reported by 47.6% of nulliparous women and by 49.7% of parous women (P = .782). We found no difference in the severity or type of urinary incontinence between these 2 groups. There was a high concordance in continence status, however, within biological sisters.

Conclusion: Vaginal birth does not seem to be associated with urinary incontinence in postmenopausal women. Considering the high concordance in continence status between sister pairs, and considering that the majority of parous women are continent, an underlying familial predisposition toward the development of urinary incontinence may be present.