Detection of raised FSH levels among older women using depomedroxyprogesterone acetate and norethisterone enanthate.

The objective of this study was to investigate whether follicle-stimulating hormone (FSH) levels can be used reliably to indicate approaching menopause in older (aged 40-49), long-term users of depomedroxyprogesterone acetate (DMPA) and norethisterone enanthate (NET-EN). One-hundred and seventeen women using DMPA, 60 NET-EN users and 161 nonusers of contraception were recruited. At recruitment, serum FSH levels were measured and questions were asked regarding menopausal symptoms, menstrual cycle and date of last injection. Results of the recruitment blood test showed that 32% of the nonusers had FSH levels in the menopausal range >25.8 mIU/mL compared to 28% of the DMPA users and 9% of the NET-EN group. After adjusting for age, there was no significant difference between the 3 groups (p = 0.13). An increase of 1 year in age increased the FSH level by 3 mIU/mL (p < 0.001). All the hormonal contraceptive users were between 1 day and 12 weeks of their injection interval. Many had been using the injectable contraceptive method for over 10 years and almost all were amenorrheic at the time of recruitment. The data show that a raised FSH level can be detected during use of DMPA and NET-EN and could be used as a menopausal indicator without interrupting method use in this group of contraceptive users.