Effects on bone mass of two oral contraceptives containing ethinylestradiol and cyproterone acetate or desogestrel: results of a 2-year follow-up.

Background: There are conflicting data about the effects of oral contraceptives on bone mass in young women. Moreover, amenorrheic women may also be affected to varying degrees by osteopenia. Both conditions (oral contraceptive use and amenorrhea) are not infrequent in women during their reproductive years.
Aim: To evaluate the safety for bone mass of two oral contraceptives, one containing cyproterone acetate and the other containing desogestrel.
Methods: A total of 67 women between 19 and 29 years of age were studied. Of these women, 35 were selected to receive an oral contraceptive containing 35 mg ethinylestradiol and 2 mg cyproterone acetate. A second group of 32 women received an oral contraceptive containing 30 mg ethinylestradiol and 150 mg desogestrel for 2 years. Immediately before and after the 12th and 24th months of therapy, bone mineral density was assessed by dual X-ray absorptiometry, and hormonal profiles and Ferriman-Gallwey scores were evaluated.
Results: After the 2-year follow-up, all subjects showed regular cycles, no pregnancies, and no changes in bone mass density. In addition, hirsute subjects showed a decrease of almost 42% in hirsutism scores.
Conclusion: Oral contraceptives containing cyproterone acetate or desogestrel in the studied doses have no deleterious effects on bone marrow.