Bilateral oophorectomy trends in Olmsted County, Minnesota, 1950-1987.

Over the 38-year period from 1950 through 1987, 1,434 Olmsted County, Minnesota women had a first unilateral oophorectomy, while 1,828 underwent bilateral oophorectomy (including 113 with a second unilateral oophorectomy). Most procedures (61% of unilateral and 87% of bilateral oophorectomies) were in conjunction with hysterectomy, and trends over time paralleled those reported for hysterectomy. Almost half of all operations (27% of unilateral and 63% of bilateral oophorectomies) were elective. The rise in bilateral oophorectomy rates over time (3.7 per 100,000 person-years per year, P = 0.016) was mostly due to elective procedures among older women, with both an increased frequency of surgery and a shift from unilateral to bilateral oophorectomy.