A recent study featured in the New York Times found that injectable contraceptives such as Depo-Provera, double the risk that women will become infected with HIV. Furthermore, if a woman is HIV positive, use of injectable contraceptives appear to double the risk that she will transmit the virus to her partner.
The study, conducted by researchers at the University of Washington, followed 3800 couples where one partner was already infected with H.I.V. The researchers tracked the couples for two years – identifying their contraceptive methods and whether or not the uninfected partner contracted HIV from the infected partner during that time.
Other studies have found similar links between increased risk for HIV transmission and injectable contraception, but this study, published in The Lancet Infectious Diseases is considered more conclusive by many experts.
Why would hormones make someone more likely to infect or transmit HIV?
Interestingly, scientists aren’t certain why hormone shots would make people more likely to get infected and transmit HIV. One theory is that the high dose of progestin – when given without estrogen – causes the vaginal tissue to become thinner, making it easier for viruses to enter and exit.
What about other hormonal contraceptives?
It is not yet known if other forms of hormonal contraceptives, such as birth control pills would also increase HIV transmission risk. The new study indicated that they might, but there weren’t enough pill users in the study to get a statistically significant result. Further research is planned.
More research is needed before any conclusive policy decisions can be made, but these findings could have a major impact on family planning recommendations, especially in populations where HIV is widespread. The study has prompted the World Health Organization to plan a meeting in January 2012 to discuss if the evidence is strong enough to advise women that hormonal injectable contraception may increase their risk of getting or transmitting HIV.
Researchers will be studying if other hormonal contraceptives such as the pill, also increase the risk of HIV transmission. If it is determined that hormonal contraceptives in general are exacerbating the spread of HIV, this could be a major health crisis in many parts of the world.