New research out of the University of California, Berkeley is linking a specific type of hormonal birth control shot with increased HIV risk. The findings stem from a meta-analysis of a dozen studies that focused on nearly 40,000 women in sub-Saharan Africa.
When compared to women who either used non-hormonal birth control or no contraception at all, women who received this type of injectable birth control experienced a 40 percent increase in the risk of acquiring HIV.
Researchers are referring to depot medroxyprogesterone acetate (also known as Depo-Provera), which is a birth control shot administered once every three months. According to Planned Parenthood, the shot works by releasing a hormone called progestin into the body. This, in turn, prevents ovulation. It also thickens the cervical mucus, which helps prevent egg fertilization.
At this point, researchers are unable to explain the link between the shot and increased HIV risk. In a UC Berkeley statement, researchers say that birth control options that contain higher levels of progestin may have “altered local immunity, increasing the risk for HIV infection.” However, this is merely one theory. They say further research is necessary to shed more light on the topic.
Even so, researchers report that abandoning this method of birth control is not warranted at this point. “There are significant risks associated with pregnancy and childbirth as well,” lead author Lauren Ralph says in a statement.
She goes on to say that ensuring a reliable supply of contraceptives to this part of the world would likely be a tricky task. For example, eliminating the Depo-Provera shot in sub-Saharan Africa may leave some women without another form of immediate birth control.
According to UC Berkeley, roughly 41 million women throughout the world use injectable forms of birth control.