Women using hormonal contraception --such as a birth control pill or a shot like Depo-Provera - are at double the risk of acquiring HIV, and HIV-infected women who use hormonal contraception have twice the risk of transmitting the virus to their HIV-uninfected male partners, according to a University of Washington-led study in Africa of nearly 3,800 couples. The study was published in The Lancet Infectious Diseases.
The research, first presented in July in Rome at the meeting of the International AIDS Society, emphasizes the need for couples to use condoms in addition to other forms of contraception in order to prevent pregnancy and HIV, said lead study author Renee Heffron, an epidemiology doctoral student working with the International Clinical Research Center at UW.
"Women should be counseled about potentially increased risk of HIV acquisition and transmission with hormonal contraception, particularly injectable methods, and about the importance of dual protection with condoms to decrease HIV risk," said Heffron.
Jared Baeten, an associate professor of global health with the International Clinical Research Center, said to his knowledge this is the first prospective study to show increased HIV risk to male partners of HIV-infected women using hormonal contraception.
More than 140 million women worldwide use hormonal contraception, including daily oral pills and long-acting injectables, like Depo-Provera.
"The benefits of effective hormonal contraception are unequivocal and must be balanced with the risk for HIV infection," said Baeten.
This study was designed to establish whether hormonal contraception increases the risk of women acquiring HIV and transmitting the virus to their male partners. The study included 3,790 heterosexual HIV serodiscordant couples (i.e. one partner with HIV infection and the other without) who were participating in two long-term studies of HIV in couples in seven African countries (Botswana, Kenya, Rwanda, South Africa, Tanzania, Uganda, and Zimbabwe).
Findings showed that using hormonal contraceptives doubled an HIV uninfected woman's chances of becoming infected with HIV. The risk was increased for both injectable (mainly depot medroxprogeterone acetate: DMPA) and oral contraceptives, although it was not statistically significant for oral contraceptives.
Additionally, women who were HIV-positive at the beginning of the study and using hormonal contraception were twice as likely to transmit the virus to their male partner compared to women who did not use hormonal contraception.
This work was funded with support from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Allergy and Infectious Diseases, the UW STD/AIDS Research Training Grant Program, and the Bill & Melinda Gates Foundation.
The International Clinical Research Center, part of the UW Department of Global Health, is conducting multiple clinical trials in Africa related to the prevention of HIV and is expanding the University of Washington's capacity to conduct pre-eminent biomedical prevention and research in infectious disease prevention.