HIV-infected women who take birth control pills are much more likely than other HIV-infected women to have detectable virus in the cervix or vagina, according to a new study. Other risk factors for viral shedding include vitamin A deficiency, gonorrhea infection, or yeast infections. Increased shedding of virus could mean a greater risk of transmission to either a sexual partner or to an infant during delivery. Heterosexual transmission of HIV is the predominant mode of infection among adults worldwide. Of children who acquire HIV-1 from their mother, 40% to 80% are estimated to become infected during delivery.
It's not clear why birth control pills, which contain synthetic estrogen and progesterone, should increase shedding of HIV in the genital tract. It's possible that the hormones influence immune system function or they may change local factors in the vagina, such as thickening cervical mucus -- which may enhance shedding of the virus. And as for vitamin A, it "has long been recognized to have a central role in maintenance of epithelial surfaces and normal function of the immune system.
The Lancet (1997;350:922-927)
COMMENT: Additional support to not use oral contraceptives. Obviously, most people who use them are not infected with HIV. However, these powerful synthetic hormones have the potential to cause serious health complications. This study is just one example of how they can disrupt normal physiology to increase HIV shedding in infected woman. If you are on them for whatever reason your long term health interests would best be served by finding a more natural option.