AIDS During Pregnancy

Heterosexual acquisition (51%) and injecting drug use (45%) are the principal modes of HIV infection in women. In 15%, no risk factor is reported or identified. Asymptomatic infection is associated with a normal pregnancy rate and no increased risk of adverse pregnancy outcomes. There is no evidence that pregnancy causes AIDS progression.

Although some fetuses appear to acquire HIV infection antenatally by transplacental transmission, approximately two-thirds are infected close to or during the time of delivery. Zidovudine (500 mg/d orally) given to the mother antenatally starting at 14 weeks of gestation and during labor (1 mg/kg/h intravenously) and then to the infant (2 mg/kg orally four times daily) for the first 6 weeks of life reduces the transmission rate from 25% to 8%.

Pregnancy does not preclude the use of combinations of highly active antiretroviral therapy (HAART). HIV-positive pregnant women should be assessed by CD4 count, plasma RNA levels, and prior or current antiretroviral use. In general, pregnant HIV-positive women should receive at least zidovudine but also HAART as appropriate for their HIV disease status after counseling regarding the potential impact of therapy on the fetus and infant after delivery. The use of prophylactic elective cesarean section before the onset of labor or rupture of the membranes to prevent vertical transmission of HIV infection from mother to fetus has been shown to reduce the transmission rate to 2% in infants of mothers taking zidovudine. There is limited information on the impact of elective cesarean section on transmission rates in infants of mothers on HAART or with viral loads less than 1000 copies/mL. However, with HAART therapy and undetectable viral loads (< 50 copies/mL), there may be no additional benefit of cesarean delivery since the calculated upper 95% confidence interval for transmission risk for vaginal delivery in such patients is < 2%. HIV-infected women should be advised not to breast-feed their infants.

ACOG committee opinion. Scheduled cesarean delivery and the prevention of vertical transmission of HIV infection. Number 234, May 2000. Committee on Obstetric Practice, Compendium of selected publications, American College of Obstetricians and Gynecologists, 2004.

Public Health Service Task Force Recommendations for Use of Antiretroviral Drugs in Pregnant HIV-1 Infected Women for Maternal Health and Interventions to Reduce Perinatal HIV-1 Transmission in the United States. http://www.hivatis.org.Watts DH: Management of human immunodeficiency virus in pregnancy. N Engl J Med 2002;346:1879.