All pregnant women should be tested for HIV so that they can begin treatment if they have HIV. If a woman is treated for HIV early in her pregnancy, the risk of transmitting HIV to her baby is extremely low (1% or less). Testing pregnant women for HIV infection and treating those women who have HIV has led to a huge decline in the number of children born with HIV.

The treatment is most effective when started as early as possible during a pregnancy. However, there are still great health benefits to beginning preventive treatment even during labor or shortly after the baby is born.