Health
Women who use hormonal contraceptives, such as birth control pills and long-acting hormone injections, are twice as likely to become infected with HIV, scientists say. In addition, researchers say that partners of HIV-positive women are much more likely to become infected with HIV if the woman uses hormonal contraceptives.
These data were obtained after a study conducted by a group of American scientists from the University of Washington, led by Dr. Jared Baeten. The study involved 3,800 couples from many countries in Africa, where hormonal contraception in the form of injections is very common.
Injectable hormonal contraception is rightly considered very convenient: in order to avoid unwanted pregnancies, it is enough for a woman to inject hormones only once every 3 months. About 12 million African women aged 15 to 49 use injectable hormonal contraception.
In each of the couples who took part in the experiment, one of the partners was HIV-positive. Couples used different types of contraception. The researchers followed the couples for 2 years. It was found that women who use hormonal contraception are twice as likely to become infected with HIV as those who use other methods to prevent unwanted pregnancies. In addition, partners of HIV-positive women were also twice as likely to become infected with HIV as partners of infected women who did not use hormonal contraception.
Scientists have yet to conduct a number of studies to find out why hormonal contraception increases the risk of HIV infection so significantly. It is believed that couples who use hormonal contraceptives are less likely to use condoms, which are known to reduce the risk of transmission. However, there is good reason to believe that there are other reasons. In particular, experiments conducted on monkeys show that the hormone progestin, which is part of hormonal contraceptives, thins vaginal tissue. By measuring the concentration of the HIV virus in the vaginal secretions of infected women, scientists found that the concentration of the virus is higher in those who use hormonal contraception. Therefore, it is not surprising that the partners of HIV-positive women who use hormonal contraceptives are more likely to become infected with the immunodeficiency virus. Interestingly, hormones do not affect the concentration of the virus in the blood in any way.
Scientists have found that oral contraceptives (birth control pills) also increase the risk of HIV infection and transmission, however, the researchers emphasize that no conclusions are yet to be drawn about birth control pills are too early, as there were too few couples who took part in the study who used oral contraception.
As it turned out, pregnancy also doubles the risk of infection and subsequent infection with a partner. However, it is not yet clear what leads to such consequences: unprotected sex or changes in a woman's hormonal background.