Bloomberg News

Contraceptive Injections Double HIV Infection Risk in Study

October 04, 2011

(Updates with Pfizer comment in sixth paragraph.)

Oct. 4 (Bloomberg) -- Using contraceptive injections such as Pfizer Inc.’s Depo Provera doubles the chance women will catch HIV and transmit it to a male partner, a study found.

Researchers from the University of Washington in Seattle followed 3,790 African couples in which one partner was infected with the AIDS-causing virus. Women who used hormone-based contraceptive injections were twice as likely to acquire and pass on HIV as those who didn’t, the researchers wrote today in the journal The Lancet Infectious Diseases. A higher risk was also observed for birth-control pills, but that finding wasn’t statistically significant, the researchers said.

The findings contradict those of previous studies, which have had inconsistent results, and suggest the active promotion of injectable contraception in Africa may be fueling the spread of the world’s biggest infectious killer, said Charles S. Morrison and Kavita Nanda, researchers at FHI 360, a nonprofit organization in Durham, North Carolina, that works on reproductive health projects.

“Conversely, limiting one of the most highly used effective methods of contraception in sub-Saharan Africa would probably contribute to increased maternal mortality and morbidity and more low birthweight babies and orphans -- an equally tragic result,” the pair wrote in an editorial accompanying the paper. They weren’t involved in the study.

Because the results came from a secondary analysis of an HIV prevention trial that wasn’t designed to examine the relationship between contraception and viral transmission, a further study crafted specifically to settle the question should now be done, Morrison and Nanda said.

“We’d prefer not to comment at this point, as we’re currently reviewing the study,” Joan Campion, a Pfizer spokeswoman, said in an e-mail.

More than 140 million women worldwide use hormonal contraception, including pills and long-acting injections, which are the most popular form of birth control in Africa, the researchers wrote. The trial was funded by the U.S. National Institutes of Health and the Bill & Melinda Gates Foundation.

--Editors: Kristen Hallam, Phil Serafino

To contact the reporter on this story: Simeon Bennett in Geneva at

To contact the editor responsible for this story: Phil Serafino at

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