June 2011

Contraception use and effectiveness among women in a trial of the diaphragm for HIV prevention

Blanchard K, Bostrom A, Montgomery E, van der Straten A, Lince N, Bruyn G, Grossman D, Chipato T, Ramjee G, Padian N. Contraception use and effectiveness among women in a trial of the diaphragm for HIV prevention. Contraception. 2011 Jun;83(6):556-63

Background: There is little data on contraceptive effectiveness or use patterns from sub-Saharan Africa.

Study Design: We analyzed data from women at risk of pregnancy (n=4905) in the Methods for Improving Reproductive Health in Africa trial of the diaphragm for HIV prevention. We described reported contraceptive method use and calculated rates of pregnancy by contraceptive method. We compared time to first pregnancy by study arm (condoms or condoms plus diaphragm), and estimated a Cox proportional hazards model to identify predictors of pregnancy.

Results: Condoms (25.8%), injectables (25.4%) and OC (21.6%) were the most commonly used methods; long-acting method use was rare. During the trial, 51.6% of women used the same method, 27.4% switched to a more effective method and 20.9% switched to a less effective method; 21.4% of women became pregnant. Pregnancy rates by contraceptive group mirrored published estimates; frequency of study product use was not associated with pregnancy.

Conclusion: Long-acting methods of contraception should be made available in HIV prevention trials and to women in Southern Africa.