Use of hormonal contraceptives and risk of HIV-1 transmission: a prospective cohort study
Renee Heffron, Deborah Donnell, Prof Helen Rees, Connie Celum, Nelly Mugo, Edwin Were, Guy de Bruyn, Edith Nakku-Joloba, Kenneth Ngure, James Kiarie, Robert W Coombs, Jared M Baeten, The Lancet Infectious Diseases, Early Online Publication, 4 October 2011
Hormonal contraceptives are used widely but their effects on HIV-1 risk are unclear. Heffron and colleagues aimed to assess the association between hormonal contraceptive use and risk of HIV-1 acquisition by women and HIV-1 transmission from HIV-1-infected women to their male partners. In this prospective study, they followed up 3790 heterosexual HIV-1-serodiscordant couples participating in two longitudinal studies of HIV-1 incidence in seven African countries. Among injectable and oral hormonal contraceptive users and non-users, they compared rates of HIV-1 acquisition by women and HIV-1 transmission from women to men. The primary outcome measure was HIV-1 seroconversion. Cox proportional hazards regression and marginal structural modelling were used to assess the effect of contraceptive use on HIV-1 risk. Among 1314 couples in which the HIV-1-seronegative partner was female (median follow-up 18·0 [IQR 12·6–24·2] months), rates of HIV-1 acquisition were 6·61 per 100 person-years in women who used hormonal contraception and 3·78 per 100 person-years in those who did not (adjusted hazard ratio 1·98, 95% CI 1·06–3·68, p=0·03). Among 2476 couples in which the HIV-1-seronegative partner was male (median follow-up 18·7 [IQR 12·8–24·2] months), rates of HIV-1 transmission from women to men were 2·61 per 100 person-years in couples in which women used hormonal contraception and 1·51 per 100 person-years in couples in which women did not use hormonal contraception (adjusted hazard ratio 1·97, 95% CI 1·12–3·45, p=0·02). Marginal structural model analyses generated much the same results to the Cox proportional hazards regression. Women should be counselled about potentially increased risk of HIV-1 acquisition and transmission with hormonal contraception, especially injectable methods, and about the importance of dual protection with condoms to decrease HIV-1 risk. Non-hormonal or low-dose hormonal contraceptive methods should be considered for women with or at-risk for HIV-1.
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Editor’s note: The issue of hormonal contraception and HIV risk continues to perplex. Observational studies have both suggested a link and not found one. This study of HIV serodiscordant couples was not specifically designed to examine this issue and had too few women on contraceptive pills to draw any conclusions. However, a doubling of the risk of HIV acquisition for HIV-negative women using injectable DMPA (depot-medroxyprogesterone acetate) and a doubling of the risk of HIV transmission from HIV-positive women using DMPA to their seronegative partners are cause for concern. Contraception improves the health of women and children worldwide and it plays a crucial role in helping women with, or at risk of, HIV infection to prevent the adverse social and health consequences of unintended pregnancies. WHO and partners are convening a technical consultation in early 2012 to re-examine the totality of evidence on the potential effects of hormonal contraception and of intrauterine devices on HIV acquisition, disease progression, and infectivity/transmission to sexual partners. The need to conduct randomized controlled trials to determine whether hormonal contraception increases the risk of HIV acquisition in women and/or of HIV transmission to men will be assessed, along with feasibility. In the meantime, we need to reinforce the importance of correct and consistent condom use, regardless of whether another method of contraception is being used. It is and has been for decades the ‘dual protection’ message.