Steroidal contraceptives: effect on bone fractures in women

Abstract

Background: Steroidal contraceptive use has been associated with changes in bone mineral density in women. Whether such changes increase the risk of fractures later in life is not clear. However, osteoporosis is a major public health concern. Age-related decline in bone mass increases the risk of fracture, especially of the spine, hip, and wrist. Concern about bone health influences the recommendation and use of these effective contraceptives globally.

Objectives: To evaluate the effect of using hormonal contraceptives before menopause on the risk of fracture in women

Search strategy: We searched for studies of fracture or bone health and hormonal contraceptives in MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS, as well as in clinical trials databases (ClinicalTrials.gov and ICTRP). We wrote to investigators to find additional trials.

Selection criteria: Randomized controlled trials were considered if they examined fractures, bone mineral density (BMD), or bone turnover in women with hormonal contraceptive use prior to menopause. Studies were excluded if hormones were provided for treatment of a specific condition rather than for contraception. Interventions could include comparisons of a hormonal contraceptive with a placebo or with another hormonal contraceptive. Interventions could also include the provision of a supplement versus a placebo.

Data collection and analysis: We assessed for inclusion all titles and abstracts identified through the literature searches with no language limitation. The mean difference was computed with 95% confidence interval (CI) using a fixed-effect model.

Main results: We found 13 RCTs, 2 of which used a placebo. No trial had fracture as an outcome but most measured BMD. Combination contraceptives did not appear to affect bone health. Of progestin-only methods, depot medroxyprogesterone acetate (DMPA) was associated with decreased bone mineral density, while results were inconsistent for implants. The two placebo-controlled trials showed BMD increases for DMPA plus estrogen supplement and decreases for DMPA plus placebo.

Authors' conclusions: Whether steroidal contraceptives influence fracture risk cannot be determined from existing information. Due to different interventions, no trials could be combined for meta-analysis. Many trials had small numbers of participants and some had large losses to follow up. Health care providers and women should consider the costs and benefits of these effective contraceptives. For example, injectable contraceptives and implants provide effective, long-term birth control yet do not involve a daily regimen. Progestin-only contraceptives are considered appropriate for women who should avoid estrogen due to medical conditions.