A retrospective cohort study of the association of parity with urinary incontinence – Does the multiparity select an urinary incontinence resistant cohort?

Before menopause 25% of women report leakage of urine, and half of young nulliparous women report occasional leakage, although few young women report daily leakage. Since stress incontinence is present in a significant number of women before childbirth, these data suggest that it may result from a series of interacting factors (genetic, anatomical); and a series of predisposing factors (pregnancy, obesity). The first vaginal delivery is more likely than any subsequent delivery to cause postpartum urinary incontinence (UI). Our question is: Does the multiparity select an UI resistant cohort? As secondary objective we analyze the classical risk factors for postpartum UI. We enrolled in our study 100 consecutive women who had delivered vaginally in 2005. 46 women are primiparous (9 have UI–20%); 43 are multiparous women without previous postparum UI (7 have UI–16%). The multiparous women with previous postpartum UI are 11 (10 have UI–91%). The difference between primiparous and multiparous women without previous postpartum UI is not significant, but the difference is significant if we compare the first and the second group with the third. The increasing age at the first pregnancy in the primiparas results to have a higher probability to develop postpartum UI (OR1.18, CI1–1.43); but in the pluriparas without previous postpartum UI the age of the mother results to be a protective factor (OR0.78, CI0.6–0.97), and also the parity seams to be protective (OR0.15, CI0.01–1.88), but not significant. We can hypothesize the existence of a natural selection capable to identify a population that for anatomical, environmental or genetic factors is more resistant to develop postpartum urinary incontinence.

Urinary incontinence risk factor - parity - postpartum urinary incontinence - stress urinary incontinence