Laboratory criteria for menopause in women using oral contraceptives.

ABSTRACT

PIP: Health workers recruited 28 women aged 35-65 attending San Francisco General Hospital in California or Magee-Women's Hospital in Pittsburgh, Pennsylvania, for a prospective study designed to evaluate the laboratory criteria for menopause in women using oral contraceptives (OCs). The first 14 women received three cycles of a triphasic OC containing 35 mcg ethinyl estradiol and 180, 215, and 250 mcg norgestimate (Orth Tri-Cyclen-28). They comprised group 1. The remaining 14 women received three cycles of a monophasic OC containing 30 mcg ethinyl estradiol and 150 mcg desogestrel (Ortho-Cept-28). They comprised group 2. 12 women in each group completed the study. The mid-cycle luteinizing hormone (LH) level was much higher in group 1 than in group 2 (8.8 vs. 3.6 mIU/ml; p = 0.02). The serum follicle stimulating hormone (FSH) level of 62.5% of the women was still less than 30 mIU/ml on day 28 of the third pill package. All the women had an FSH:LH ratio of 1 at baseline and on day 28 of the third OC package, indicative of menopause. This ratio was significantly higher on day 7 of the pill-free interval than at baseline or mid-cycle (2.82 vs. 1.99 and 2.26, respectively; p 0.0001). The proportion of women with estradiol levels of 25 pg/ml was 90% at baseline and in the middle of the third cycle and 95% at the end of the pill-free interval of the third cycle. These findings suggest that the mid-cycle FSH:LH ratio and measuring FSH on the seventh day of the pill-free interval are not reliable indicators of menopause. Instead, a serum FSH:LH ratio of 1 or an estradiol level of 20 pg/ml on the seventh day of the pill-free interval may be a more reliable indicator of menopause in women using OCs in their later reproductive years.