Vaginal parity and pelvic organ prolapse

To investigate whether the odds of pelvic organ prolapse vary significantly with the number of vaginal births and whether cesarean birth is associated with prolapse.

In this cross-sectional study of women over the age of 40, pelvic organ prolapse was defined as descent to or beyond the hymen. Logistic regression was used to estimate the relative odds of pelvic organ prolapse for each vaginal birth or cesarean birth, controlling for confounders.

Two hundred ninety women underwent a pelvic organ prolapse quantification POPQ examination, and 72 were found to have pelvic organ prolapse. A single vaginal birth significantly increased the odds of prolapse (OR 9.73, 95% CI 2.68-35.35). Additional vaginal births were not associated with a significant increase in the odds of prolapse. Cesarean births were not associated with prolapse (OR 1.31, 95% CI 0.49-3.54).

The odds of pelvic organ prolapse were almost 10 times higher after a single vaginal birth. The marginal impact of additional births on this association was small.