For the past two decades, scientists have debated, quite angrily at times, whether the use of hormonal contraceptives increases a woman’s risk of HIV. Until now, the research has been inconclusive, but a new study from UC Berkeley may decide the matter. Women using the birth control shot (Depo-Provera or depot medroxyprogesterone acetate) have an increased risk of HIV, the researchers found. Remarkably, other forms of hormonal contraception, including the pill, do not appear to increase this risk.
“Whether the risks of HIV observed in our study would merit complete withdrawal of depot medroxyprogesterone acetate needs to be balanced against the known benefits of a highly effective contraceptive,” wrote the study authors in their concluding remarks.
Worldwide about 144 million women use hormonal contraception, which either prevents egg production or stops fertilization of an egg from taking place. Of the total women using hormonal forms of birth control, nearly 103 million women take a pill, while about 41 million use injectable forms, either Depo-Provera, which lasts for 12 weeks, or Noristerat, which lasts for eight weeks. Contraceptive injections are known to be more than 99 percent effective, however the downside is the shots may disrupt a woman’s cycle, affect her estrogen production (resulting in bone thinning), and cause her to gain weight. Scientists also have suggested the shots may increase risk of HIV infection, although until now, this has not been clear.
The Current Study
To understand, then, whether millions of women might be placing themselves at greater risk for HIV, a team of UC Berkeley researchers analyzed the results of 12 studies from sub-Saharan Africa involving more than 39,500 women. In 10 studies of Depo-Provera, the team found evidence of an increased HIV risk, yet there was no similar risk increase with oral contraceptive pills. All told, a woman's chance of becoming infected with HIV increased by 40 percent when using the birth control shot, compared to women using either other contraceptive methods or no birth control at all.
“Banning DMPA would leave many women without immediate access to alternative, effective contraceptive options,” Dr. Lauren Ralph, lead author and an epidemiologist at UC Berkeley, stated in a press release. “This is likely to lead to more unintended pregnancies, and because childbirth remains life-threatening in many developing countries, could increase overall deaths among women.”
Source: Ralph LJ, McDoy SI, Shiu K, Padian NS. Hormonal contraceptive use and women's risk of HIV acquisition: a meta-analysis of observational studies. The Lancet: Infectious Diseases. 2015.