Laboratory criteria for menopause in women using oral contraceptives

Objective: To evaluate laboratory criteria for menopause in women taking oral contraceptives (OC). Design: Prospective, uncontrolled pilot study. Setting: San Francisco General Hospital, San Francisco, California, and Magee-Womens Hospital, Pittsburgh, Pennsylvania. Patients: Twenty-eight menopausal women. Interventions: Fourteen menopausal women received triphasic 35 μg ethinyl E2 and 180-215-250 μg norgestimate, and 14 menopausal women received monophasic 30 μg ethinyl E₂150 μg desogestrel. Main Outcome Measures: Serum FSH, LH, and E₂ levels were evaluated on days 14 and 28 (day 7 of the pill-free interval) of the third cycle of pills. Results: Twelve women in each group completed the study. Fifteen (62.5%) subjects still had a serum FSH <30 mIU/mL (30 IU/L) on the 7th day of the pill-free interval of the third pill package. All subjects had a serum FSH:LH ratio >1 and 20 of 21 (95%) subjects had E₂ < 20 pg/mL (73 pmol/L) at the end of the pill-free interval of the third cycle. Conclusions: Measuring FSH on the 7th day of the pill-free interval is not a sensitive test for menopause. Serum FSH:LH ratio >1 or E₂ < 20 pg/mL (73 pmol/L) on the 7th day of the pill-free interval may be a more appropriate marker of menopause in women using OC in the later reproductive years.