If a pregnant woman is found to be HIV-positive, it is critical to preserve and improve the mother’s health as well as to decrease the risk of transmission of the virus to the infant. HIV-positive pregnant women should receive medical care and extended social support, including an assessment of the family’s living situation, nutritional assistance, and testing of any children and sexual partner(s). If the mother’s immunologic state is deemed poor based on CD4 monitoring or clinical status, three antiretroviral medications should be started as soon as possible per Protocol 2.3. Alternatively, if the mother is not ill, ART can be deferred until the 28^th week of gestation, then administered to prevent MTCT of HIV.

Nutritional supplementation should be provided to pregnant women beginning at the 12^th week of gestation and continued through the pregnancy. This supplementation should be in the form of a daily multivitamin containing B1 (20 mg), B2 (20 mg), B6 (25 mg), niacin (100 mg), B12 (50 mcg), C (500 mg), E (30 mg), and folic acid (0.8 mg). This regimen has been found to reduce the risk of fetal death, severe preterm birth, small size for gestational age, and low birth weight among children of HIV-positive women.⁷⁷ Because vitamin A has been shown to increase the risk of MTCT of HIV, particularly in women who take it during breastfeeding,⁷⁸ nutritional supplements that include vitamin A should not be given.

The presence of STIs, anemia, increased viral load, and low CD4 count have all been associated with increased rates of HIV transmission from mother to child and should be addressed accordingly.^79–82 Obstetric risk factors for transmission include prolonged rupture of amniotic membranes, vaginal rather than elective cesarean delivery (in particular, among women not receiving ART), chorioamnionitis, and obstetric complications.^83–85 Thus, the provision of obstetrical services should be improved concurrently with the scale-up of ART if maternal mortality and vertical transmission of HIV are to be decreased.

Prenatal testing, prenatal care, and appropriate screening and treatment for STIs are clearly linked to better outcomes. However, of all known factors, high maternal viral load is the strongest predictor of vertical HIV transmission. Specifically, the risk of MTCT is increased 2.4-fold for every log increase in viral load at the time of delivery.⁸⁶ Antiretroviral therapy is thus the most important intervention for pMTCT.