Forearm bone density in users of Depo-Provera as a contraceptive method

Objective: To determine the influence of depot medroxyprogesterone acetate (MPA) on bone mineral density when used as a contraceptive method. Design: Cross-sectional study. Setting: Academic tertiary-care hospital. Patient(s): Fifty premenopausal women who had used depot MPA as a contraceptive method for greater than or equal to 1 year and 50 women who had never used hormonal contraceptive methods. Intervention(s): Bone mineral density was evaluated at the midshaft and at the distal radius of the nondominant forearm using single x-ray absorptiometry. Main Outcome Measure(s): Bone mineral density. Result(s): Bone mineral density at the midshaft of the forearm was lower in depot MPA users than in women who had never used hormonal contraceptive methods, but the difference was not statistically significant. At the distal portion, bone mineral density was significantly lower in the study group. The duration of depot MPA use was not related to bone mineral density. Conclusion(s): Women greater than or equal to 35 years of age presented with a lower bone mineral density only at the distal portion of the forearm after the use of depot MPA for greater than or equal to 1 year. However, this decrease was not related to the duration of depot MPA use. It is not possible to conclude that women who use depot MPA are at risk of osteoporosis. (C) 1999 by American Society for Reproductive Medicine.