Antiretroviral therapy can reduce the risk of mother-to-child transmission of HIV. This was first demonstrated with the publication of the ACTG 076 trial in 1994, in which AZT (zidovudine, Retrovir) reduced the risk of transmission by two-thirds when it was given orally to the mother during pregnancy, intravenously during labour, and orally to the infant for the first six weeks after childbirth.^[1]

Since that time, a number of major studies with antiretroviral drugs have been conducted in developed countries as well as in resource-limited settings. These clinical trials have compared or added other antiretrovirals to AZT or nevirapine (Viramune), in breastfeeding and non-breastfeeding populations. They have investigated aspects such as the best time to start treatment for preventing transmission as well different approaches to treatment during labour or after childbirth. Recent studies have also explored ways to reduce the development of antiretroviral resistance associated with treatment to prevent mother-to-child transmission that could limit a woman's future treatment options.

As a result of this research, treatment protocols (often called short courses or sc) have been improved to the point where the rate of mother-to-child transmission has been reduced to less than 4% in some clinical trials, where ART is given from the third trimester, maternal HAART is available as needed, and prophylaxis is given to the mother and nursing infant.