1. In addition to the use of antiretroviral drug regimens for either treatment of the mother’s health or prophylaxis to prevent mother-to-child transmission of HIV, elective cesareans (if safely available) may further reduce the risk of vertical transmission.
A study of a cohort of 453 pregnant women living with HIV in Brazil found that HAART and elective Cesarean section reduced the risk of vertical transmission. Data from 401 infants born between 2000 and 2009 was analyzed, of whom 15 acquired HIV and 386 infants remained HIV-negative. Use of HAART for longer periods and elective Cesarean section were associated with a lower risk of vertical transmission. The rate of vertical transmission was 3.74% and the mean CD4 cell count of HIV pregnant women was 474 cells/mm3, with 70.3% having an undetectable viral load in the third trimester. For women with CD4 cells below 350, the risk of vertical transmission was increased 12-fold. HAART use for less than 15 days prior to delivery increased the risk of vertical transmission 15 fold. Vaginal delivery after the onset of labor increased the risk of vertical transmission five-fold.
Because the risk of perinatal transmission of HIV is directly proportional to maternal viral loads, for women who have either very low or undetectable viral loads, there may be no additional benefit to cesarean section delivery. “For those [women] on highly active antiretroviral therapy who have undetectable or low viral loads, the added benefit of cesarean delivery is not established and is probably negligible” (Sharma and Spearman, 2008: 414).