Several factors, including timing of ART initiation, pretreatment viral load and ART adherence, were associated with a detectable viral load at delivery among pregnant women with HIV, according to data published in Annals of Internal Medicine.
“We found that 13% of women had detectable virus in their blood at the time of delivery, despite receiving effective treatment during pregnancy,” Ingrid Katz, MD, MHSc, assistant professor of medicine at Harvard Medical School and associate physician in the division of women’s health at Brigham and Women’s Hospital, told Infectious Disease News. “Although most of these newborns were not infected, we know that children exposed to HIV in utero are at higher risk for developing infections.”
Katz and colleagues conducted a multicenter observational study that included 671 women who had enrolled in the IMPAACT Group Protocol 1025 from October 2002 to December 2011. The HIV-positive pregnant women were eligible if they were ART-naive before pregnancy, initiated ART during the index pregnancy and had viral load data within 14 days before delivery or 7 days after delivery.
Eighty-eight women (13.1%) had a detectable viral load at delivery. In a multivariable analysis, multiparity, black ethnicity, education level at or below 11th grade, initiating ART in the third trimester, and having the first prenatal visit in the third trimester were associated with detectable viral load at delivery. In a multivariable analysis of treatment characteristics, women with at least one treatment interruption were more likely to have a detectable viral load at delivery. Among a subset of women with adherence data, nonadherence to ART also was associated with detectable viral load.
Katz said that women who received less potent ART regimens also had a higher probability of having a detectable viral load at delivery, as did women with higher pretreatment viral loads.
“These findings are important because they suggest that antiretroviral treatment can only achieve its optimal efficacy if HIV-positive individuals initiate treatment early and adhere to their medications throughout pregnancy,” Katz said. “They also underscore the importance of starting women on the most potent regimens available.”
The updated US Department of Health and Human Services guidelines from July 2012 recommend starting ART in the first trimester, or delaying until 12 weeks gestation depending on CD4+ cell count, HIV RNA levels; and maternal conditions.
“We believe these data will help physicians consider the optimal timing of ART in pregnancy among women living with HIV,” Katz said. “Ideally, women should start before the third trimester, and it is likely that the earlier they start, the better their outcome will be. However, it is important to note that the benefits of earlier ART initiation must be weighed against potential risks of drug exposure to the fetus during the first trimester.” – by Emily Shafer
Disclosure: Katz reports no relevant disclosures.