Natural history of pelvic organ prolapse in postmenopausal women.

OBJECTIVE: To describe the natural history of pelvic organ prolapse and risk factors for changes in vaginal descent in older women.

METHODS: This 4-year prospective observational study included 259 postmenopausal women with a uterus enrolled at one Women's Health Initiative clinical site who completed at least two annual pelvic organ prolapse quantification (POP-Q) examinations. We calculated 1-year and 3-year incidence and resolution risks for prolapse (defined as maximal vaginal descent to or beyond the hymen) and estimated progression and regression rates (1 cm or greater and 2 cm or greater changes in maximal vaginal descent) and risk factors.

RESULTS: Mean age was 68.1+/-5.5 years, and median vaginal parity was 4. Seventy-three (28%) women had four exams, 128 (49%) had three exams, and 58 (22%) had two exams. Prolapse waxed and waned yearly in individual women. Overall 1-year and 3-year prolapse incidences were 26% (95% confidence interval [CI] 20-33%) and 40% (95% CI 26-56%); 1-year and 3-year prolapse resolution risks were 21% (95% CI 11-33%) and 19% (95% CI 7-39%). Rates of any change in maximal vaginal descent over time varied depending on baseline measurements. Over 3 years, the maximal vaginal descent increased by at least 2 cm in 11.0% (95% CI 4.9-20.5%) of the women and decreased by at least 2 cm in 2.7% (95% CI 0.3-9.5%). Increasing body mass index and grand multiparity increased the risk for vaginal descent progression.

CONCLUSION: Prolapse progresses and regresses in older women, although rates of vaginal descent progression are slightly greater than regression overall. Obesity is a risk factor for progression in vaginal descent.

LEVEL OF EVIDENCE: III.