Combination Antiretroviral Use and Preterm Birth

Background. Use of antiretroviral drugs (ARVs) during pregnancy has been associated with higher risk of preterm birth. Methods. The Pediatric HIV/AIDS Cohort Study network's Surveillance Monitoring for ART Toxicities study is a US-based cohort of human immunodeficiency virus (HIV)-exposed uninfected children. We evaluated maternal ARV use during pregnancy and the risk of any type of preterm birth (ie, birth before 37 completed weeks of gestation), the risk of spontaneous preterm birth (ie, preterm birth that occurred after preterm labor or membrane rupture, without other complications), and the risk of small for gestational age (SGA; ie, a birth weight of <10th percentile for gestational age). Multivariable logistic regression models were used to evaluate the association of ARVs and timing of exposure, while adjusting for maternal characteristics. Results. Among 1869 singleton births, 18.6% were preterm, 10.2% were spontaneous preterm, and 7.3% were SGA. A total of 89% used 3-drug combination ARV regimens during pregnancy. In adjusted models, the odds of preterm birth and spontaneous preterm birth were significantly greater among mothers who used protease inhibitors during the first trimester (adjusted odds ratios, 1.55 and 1.59, respectively) but not among mothers who used nonnucleoside reverse-transcriptase inhibitor or triple-nucleoside regimens during the first trimester. Combination ARV exposure starting later in pregnancy was not associated with increased risk. No associations were observed between SGA and exposure to combination ARV regimens. Conclusions. Protease inhibitor use early in pregnancy may be associated with increased risk for prematurity.