Prevention of perinatal HIV transmission during pregnancy.

Transmission of the human immunodeficiency virus (HIV) from mother to child can occur in utero, during labour or after delivery from breastfeeding. The majority of infants are infected during delivery. Maternal HIV-1 plasma viral load at delivery is the most important predictor of vertical transmission. For this reason, efforts to interrupt transmission have focused on the use of antiretroviral therapy. Zidovudine has been shown to reduce significantly vertical HIV transmission when used antepartum and intrapartum by the mother and postpartum by the newborn for 6 weeks. However, zidovudine monotherapy increases the risk of developing zidovudine resistance and may jeopardize the goal of durable viral suppression and allow HIV disease progression in the mother and transmission to the infant. Potent antiretroviral therapy is now recommended for all HIV-infected pregnant women using the same criteria for non-pregnant individuals. If possible, combination antiretroviral regimens should include the use of zidovudine but not at the expense of long-term viral suppression. The use of elective Caesarean section should probably be reserved for women who fail to achieve viral suppression at the time of delivery or if indicated for obstetrical reasons. The practice of breastfeeding has been shown to diminish the long-term efficacy of perinatal antiretroviral therapy. All HIV-infected mothers should avoid breastfeeding the newborn if possible. This review summarizes major prospective and retrospective antiretroviral treatment studies in HIV-infected pregnant women. Pharmacokinetic information as it relates to pregnancy and adverse event profiles of antiretroviral agents are also discussed. The impact of recent advances in the management of HIV infection in pregnancy is discussed with regard to their feasibility in resource-poor countries.