Using hormonally based birth control nearly doubles the risk an uninfected woman will contract HIV or that an infected woman will transmit the virus to her partner, researchers said Wednesday. Researchers had suspected such a link in the past, but the new study in Africa is the first to confirm their suspicions.
Dr. Renee Heffron of the University of Washington and her colleagues studied nearly 2,500 HIV-positive women in seven African countries -- Kenya, Uganda, Rwanda, Botswana, Zambia, Tanzania and South Africa -- from 2004 to 2010. All their male partners were HIV-negative at the beginning of the study. Heffron reported at the Rome meeting of the International AIDS Society that 2.61% of the men whose partner used a hormonal birth control method contracted the virus, compared with 1.51% of the men whose partner used a physical barrier or no contraception.
The team also studied about 1,300 couples in which the man was infected but not the woman. They found that 6.6% of the women using hormonal birth control became infected within a year, compared with 3.8% of those not using the pills or shots.
Heffron warned women about discontinuing their contraception, however, urging that they balance the risks of becoming infected with those of becoming pregnant.
Researchers don't know precisely how the drugs increase the risk of infection. Earlier studies, however, showed an increase of HIV-infected cervical cells in HIV-positive women after they began using hormonal contraception.