Usefulness of FSH measurements for determining menopause in long-term users of depot medroxyprogesterone acetate over 40 years of age

Abstract

Objective To assess the usefulness of follicle-stimulating hormone (FSH) measurements for determining menopause in 40–55-year-old users of depot medroxyprogesterone acetate (DMPA). Study Design FSH levels were measured in 355 blood samples from 82 amenorrheic women during an 18-month period. Blood was collected every 90 days immediately prior to DMPA administration. Results Using FSH values >35 mIU/mL as being in the post menopausal range, 32 women (39.0%) presented at least one FSH measurement in the postmenopausal range and 14 of them (43.7%) had more than one elevated FSH measurement and were considered postmenopausal. In five users (15.6%), only the last FSH measurement was within the postmenopausal range, and in 13 women (40.6%), FSH returned to normal values following one measurement that was within the postmenopausal range. Conclusions The menopausal status in DMPA users in amenorrhea should be determined based on at least two consecutive high FSH evaluations, since, as shown here, 40.6% of the women with high FSH had a low FSH in the subsequent determination. FSH measurements should be done only in women ≥50 years old because there is a greater possibility of being in postmenopause. However, we do not recommend the interruption of DMPA use prior to the quantification of FSH.