Effects of bilateral salpingo-oophorectomy at the time of hysterectomy on pelvic organ prolapse: results from the Women's Health Initiative trial.

OBJECTIVE This study aims to estimate the effects of bilateral salpingo-oophorectomy (BSO) at the time of hysterectomy and estrogen therapy on vaginal prolapse. METHODS A retrospective analysis of the Women's Health Initiative estrogen-alone trial was performed. Women who retained their ovaries were compared with women who had BSO at the time of hysterectomy for the presence of cystocele or rectocele at entry into the study. Based on BSO and hormone therapy (HT) status, participants were categorized into groups. We hypothesized that BSO and prolonged hypoestrogenemia may be associated with an increased risk of prolapse. Univariate and multivariate analyses were used to determine the effects of BSO and HT status on cystocele and rectocele. RESULTS Of 10,739 participants in the estrogen-alone trial, 8,879 women were included in the analysis. Older age, higher parity, higher body mass index, higher waist-to-hip ratio, and non-African-American race/ethnicity were associated with increased odds of developing cystocele or rectocele. Women who retained their ovaries had higher rates of cystocele or rectocele at screening (39%) compared with all women who had BSO (31-36%; odds ratio, 1.18; 95% CI, 1.04-1.33). After controlling for multiple variables, our analysis showed that women who retained their ovaries had higher odds of developing cystocele or rectocele compared with women who had BSO and no subsequent HT (odds ratio, 1.23; 95% CI, 1.07-1.41). All other comparisons were nonsignificant. CONCLUSIONS BSO at the time of hysterectomy is not associated with increased risk of cystocele or rectocele. BSO and no subsequent HT may even have a protective effect against cystocele or rectocele.