The most popular contraceptive for women in eastern and southern Africa, a hormone shot given every three months, appears to double the risk of HIV infection among users, according to a large study published Monday. And when it is used by HIV-positive women, their male partners are twice as likely to become infected than if the women had used no contraception.
The findings potentially present an alarming quandary for women in Africa. Hundreds of thousands of them suffer injuries, bleeding, infections and even death in childbirth from unintended pregnancies. Finding affordable and convenient contraceptives is a pressing goal for international health authorities.
But many countries where pregnancy rates are highest are also ravaged by HIV. So the evidence suggesting that the injectable contraceptive has biological properties that may make women and men more vulnerable to HIV infection is particularly troubling.
“The best contraception today is injectable hormonal contraception because you don’t need a doctor, it’s long-lasting, it enables women to control timing and spacing of birth without a lot of fuss and travel,” said Isobel Coleman, director of the women and foreign policy program at the Council on Foreign Relations. “If it is now proven that these contraceptions are helping spread the AIDS epidemic, we have a major health crisis on our hands.”
Injectable hormones are very popular. About 12 million women between the ages of 15 and 49 in sub-Saharan Africa, roughly 6 percent of all women in that age group, use them. In the United States, it is 1.2 million, or three percent of women using contraception. While the study involved only African women, scientists said biological effects would likely be the same for all women. But they stressed that concern is greatest in Africa because the risk of HIV transmission from heterosexual sex is so much higher than elsewhere.
The study, which several experts said added significant heft to previous research while still having some limitations, has prompted the World Health Organization to convene a meeting in January to consider if evidence is now strong enough to advise women that the method may increase their risk of getting or transmitting HIV.
“We are going to be re-evaluating WHO’s clinical recommendations on contraceptive use,” said Mary Lyn Gaffield, an epidemiologist in the World Health Organization’s department of reproductive health and research. The injectable is “something that a woman can do privately herself and it doesn’t need to be remembered to be taken every day. It’s also a relatively inexpensive method.”