The most popular contraceptive for women in eastern and southern Africa, a hormone shot given every three months, appears to double the risk the women will become infected with H.I.V., according a large study published Monday. And when it is used by H.I.V. 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 contraceptives that are affordable and convenient is a pressing goal for international health authorities.