Contraception and women's HIV risks

Ugandan and US scientists working in the Rakai District have reported on the relationship between HIV risk and use of different forms of contraception. The Rakai Project Study Group has analysed data including repeated HIV test results from more than 5,000 initially HIV-negative sexually active women aged 15-49, who had access to a range of contraceptive methods. Women were asked detailed questions about their contraceptive use, sexual behaviour and sexual health.

During the study, 202 women became HIV-positive, corresponding to an incidence rate of 1.5% per person year. Of those 202 women, 159 were not using any hormonal contraception or condoms at the time, 12 were using the pill, 16 injectable contraception (mostly Depo-Provera) and 15 were using condoms (inconsistently). These numbers allowed the incidence rates of HIV to be compared between groups of women using the different forms of contraception, although not necessarily between different kinds of oral contraceptive.

Initial comparisons showed a higher incidence of HIV among contraceptive users, although this difference was not statistically significant. After adjusting for numbers of sexual partners, marital status, age, and the presence of genital ulcer disease, it was found that use of hormonal contraceptive pills or injections did not increase or decrease the risk of HIV infection among sexually active women aged 15-49 in this study. Reported ‘inconsistent’ condom use also had no impact on HIV risk (in fact, HIV incidence was relatively high in this group), though among the 350 women who reported ‘consistent’ condom use none became HIV-positive. Women who used oral contraceptives were more likely to report some condom use than women who did not use oral contraceptives.

The last finding points to the significance of this study. Hormonal contraception provides the best protection for many women against unwanted pregnancy and condoms provide the best protection for many women against HIV and other STIs. While this study is not absolutely conclusive, since women who chose different kinds of contraception differed in their sexual behaviour and other risk factors, it is probably the best evidence that will ever be available, to show that hormonal contraceptives do not increase HIV risk.

Among women with HIV who have access to treatment, further issues arise since some ARVs may reduce the effectiveness of hormonal contraceptives. This is discussed in relation to individual drugs on aidsmap.

A NAM factsheet on pregnancy and contraception, written for women with HIV in the UK, is available as a pdf file here and as a web page here.