Researchers conducted a meta-analysis of 18 studies measuring rates of HIV infection among women using hormonal forms of contraception in sub-Saharan Africa. Individual participant data (IPD) was available for a total of 37,124 women aged 15-49, of whom 1,830 became infected with HIV.
“Contraception has profound benefits for women and societies,” write the authors, “including reduced maternal and infant mortality and morbidity, empowerment of women to make choices about fertility, associated economic improvement, and a reduction in the number of babies born with HIV.”
However, users of the injectable progestin contraceptive depot-medroxyprogesterone acetate (DMPA) appeared to be 50% more likely to develop an HIV infection than women who were not using any form of hormonal contraception.
Injectable hormonal contraception works by preventing ovulation and altering the lining of the womb so that pregnancy cannot occur. In particular, DMPA is used by around 41 million women around the world.
No increased risk of HIV infection was observed by the study authors among women using other forms of injectable hormonal contraception – norethisteroneenanthate (NET-EN) or a different injectable progestin – or combined oral contraceptives (COC).
DMPA users were also 43% more likely than COC users to become infected with HIV, and 32% more likely than NET-EN users. The authors calculated these risk percentages after controlling the data for factors that could influence HIV risk, such as condom use and number of sexual partners.