Premenopausal bone loss and depot medroxyprogesterone acetate administration.

A 39-year-old woman on depot medroxyprogesterone acetate for 17 years developed multiple fractures after falling from a stationary horse. Densitometry revealed significant osteopenia. Although the reported patient was a thin, Caucasian woman, she did not have any other significant risk factors for osteoporosis except for a possible state of partial estrogen deficiency induced by the use of depot medroxyprogesterone acetate. Studies have shown that the estradiol levels of premenopausal women who have received this hormonal contraceptive for more than 1 year never reach those seen in the mid-cycle or luteal phase of the normal menstrual cycle. The estradiol levels are comparable only with those found in the early follicular phase. Therefore, women who use depot medroxyprogesterone acetate are in a state of partial estrogen deficiency, which may be associated with increased bone loss.