Ovarian surgery for bilateral endometriomas influences age at menopause.

BACKGROUND Questions remain as to whether surgical excision of ovarian endometriomas might cause damage to ovarian function. To test the hypothesis that ovarian surgery for endometrioma compromises ovarian function and accelerates ovarian failure. METHODS In a tertiary university Clinic, longitudinal prospective cohort study. Patients who underwent laparoscopy for endometriosis between March 1993 and November 2007 were assessed for inclusion in the study. A prospective follow-up at 3, 6 and 12 months then yearly was conducted. Evolution of menstrual pattern, symptoms and reproductive outcomes were investigated. RESULTS From over the 14-year period, 302 patients were included in the study. The mean age (±SD) of patients was 32.6 ± 5.6 years; the median duration of follow-up was 8.5 years (range 2-17 years). Menopause was documented in 43 women (14.3%) at a mean age of 45.3 ± 4.3 years (range 32-52 years). Women previously submitted to bilateral cystectomy were younger at menopause than those with monolateral endometrioma (42.1 ± 5.1 years versus 47.1 ± 3.5 years, P = 0.003). Premature ovarian failure (POF) was observed in 7 of 43 (16.3%) menopausal patients; the majority (4, 57.1%) after bilateral cystectomy. The relationship between the preoperative ovarian endometriomas total diameter and menopausal age was significant in case of surgery for bilateral endometriomas (R(2) = 0.754, P = 0.002). CONCLUSIONS Patients who had been operated on for bilateral endometriomas have an increased risk of POF. Ovarian parenchyma loss at the time of surgery seems related to cyst diameter. In the case of unilateral ovarian endometrioma, the contralateral intact ovary might adequately compensate.