The Depo-Provera birth control shot was tied to a greater HIV risk in a new study.
Researchers analyzed 12 studies including almost 40,000 women who were HIV-negative when the studies began. In two studies (a total of 2,100 women) the woman's partner had already been diagnosed with HIV.
The studies were all conducted in Africa where this form of birth control is highly depended on and the HIV virus is much more prevalent than other countries, reported Health Day.
"Within each specific population, some groups are affected more than others. DMPA users were 40 percent more likely to be infected than nonusers, even though the risk of HIV in both groups remains low," Lauren Ralph, the lead author of the review, told Medscape.
Although the risk for HIV is high, Ralph says the birth control should still be used - particularly in areas like Africa where there isn't a big selection on different methods of birth control.
Injectables, such as Depo-Provera, are taken by about 41 million women worldwide for birth control, according to the review.
It's speculated by health experts that Depo-Provera may increase a woman's odds of contracting HIV because the shot comprises hormone combinations that might alter a woman's genital tract, immune system or vaginal bacteria, which could change her likelihood of getting HIV.
The reason for the increased chance of contracting HIV is not discussed in the review.
DepoProvera's maker "is not aware of any scientific evidence showing a causal association between use of hormonal contraceptives and an increase in HIV transmission rates," according to a statement.
The review findings were published January 8 in Lancet Infectious Diseases.
