Approximately 10 percent of U.S. women 15 to 19 years of age use depot medroxyprogesterone (DMPA; DepoProvera) for contraception. Recent studies have shown that DMPA has an adverse impact on bone mineral density. This is of particular concern in young women because peak bone mass is developed at this age. Any negative impact on peak bone mass at this time could result in increased bone fracture risk later in life. Studies have shown that bone density loss occurs in young women who use DMPA, but one study found a significant gain in bone mineral density after discontinuation of DMPA. Scholes and associates conducted a population-based prospective cohort study to evaluate bone mineral density changes in young women during and after use of DMPA.

The trial participants were adolescents 14 to 18 years of age. Two groups were recruited for the study; the groups consisted of those who were using DMPA for contraception and those who were not. The participants were evaluated at baseline and every six months for at least 24 months. The evaluation included questionnaires covering health history, pregnancy history, contraception, smoking, physical activity, alcohol use, caffeine intake, demographic details, and food-intake frequency for the preceding 30 days. The participants’ height, weight, and bone mineral density of the hip, spine, and whole body also were assessed. The main outcome measure was the change in bone mineral density during the study period.

Eighty young women in the DMPA group and 90 in the comparison group were included in the final analysis. Of the women in the DMPA group, 61 stopped using it during the follow-up period. The young women who used DMPA had a significant decrease in their bone mineral density at the hip and spine compared with those who did not use DMPA. There was no significant difference in whole-body bone mineral density measurements between the groups. Participants who had not used DMPA previously had a significant loss of bone mineral density compared with those with a history of DMPA use. The young women who discontinued DMPA use during the study had a significantly increased bone mineral density at all three sites compared with the control group.

The authors conclude that DMPA use in young women causes significant bone mineral density loss at the hip and spine. They also note that there are significant gains in bone mineral density when DMPA is discontinued, suggesting that the bone mass loss is reversible.