Hormone-based contraception was associated with an increased risk of HIV acquisition and transmission in a study presented at the recently concluded 6th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention. The prospective study followed 3,790 heterosexual serodiscordant couples in seven African countries for two years.
One group included nearly 2,500 HIV-infected women, of whom about one-third took hormonal contraception such as daily oral pills or an injectable form at least once, typically in the form of shots taken every few months. If the woman used hormone-based contraception, her uninfected male partner had a 2.61 percent chance of acquiring HIV within a year, compared with a 1.51 percent chance if she did not take such contraception.
In a second group of about 1,300 couples in which the men were HIV-infected but the women were not, about 20 percent of the women took hormonal contraception, mostly shots. The chance of becoming infected was 6.6 percent for women taking hormone-based contraception, compared with 3.8 percent for women who did not.
The study took into account condom use, sexual behavior and other risk factors to rule out alternate reasons for the differences in HIV risk. However, the findings still need to be confirmed in follow-up studies and should not cause women to immediately change birth control practices, the researchers said.
In many parts of the world, a potential increased risk of HIV would have to be weighed against the consequences of unintended pregnancy, including maternal mortality and poverty, the study authors said.
"Contraception is incredibly important to economic and social development of women and children worldwide," said co-investigator Dr. Jared Baeten of the University of Washington.
To view the abstract of the study, "Hormonal Contraceptive Use and Risk of HIV-1 Transmission: A Prospective Cohort Analysis," visit http://pag.ias2011.org/abstracts.aspx?aid=1715.