Negative BMD effects of depot contraception are reversed on discontinuation

The use of depot medroxyprogesterone acetate contraception (DPMA) in adolescents is associated with a significant and continuous loss of bone mineral density at the hip and spine. However, new research suggests that this effect is reversed on discontinuation.

In introducing their study the authors reflect on previous research, which reported an association between contraception with DMPA and decreased BMD. In particular, the investigators express concern that adolescents may be particularly affected.The current study, led by Dr Scholes from the Group Health Cooperative (Seattle, USA), evaluated BMD changes in adolescents using and discontinuing DMPA contraception.In total, 80 adolescent DMPA users (aged 14 to 18 years) were compared with 90 age-matched unexposed controls. In these participants BMD was measured every six months at the hip, spine, and whole body for 24 to 36 months.During follow-up, 61 of the users discontinued DMPA. Compared with controls, DMPA users experienced a significant drop in BMD at the hip and spine (p<00.1 for both), but not for the whole body (p=0.78), the investigators report. Moreover, bone loss occurred more rapidly in newusers than in prevalent users.However, the results identify that those discontinuing treatment experienced significantly increased bone mineral density relative to non-users at all anatomical sites."These findings are reassuring for those concerned about future risk of fractures," Dr Scholes comments, adding that the information can be useful in helping young women balance the need to avoid unintended pregnancies with the need to build strong bones.The authors continue by highlighting the increasing public health importance of osteoporosis, noting that, "factors that may affect peak bone mass attainment and maintenance have received deservedly greater emphasis."(Source: Scholes, D. Lacroix, A. Ichikawa, L. et al. 2005, 'Change in bone mineral density among adolescent women using and discontinuing depot medroxyprogesterone acetate contraception', Archives of Pediatrics &Adolescent Medicine, vol. 159, pp. 139-144.)