International AIDS Society

1st-Trimester Protease Inhibitors Raise Risk of Preterm Birth in US

Author: Mark Mascolini

22 February 2013

Preterm birth was more than 50% more likely when HIV-positive mothers took a protease inhibitor (PI) in the first trimester of pregnancy, but not later in pregnancy. Taking a nonnucleoside (NNRTI)-based regimen did not raise chances of preterm birth.

Researchers in the Pediatric HIV/AIDS Cohort Study network's Surveillance Monitoring for ART Toxicities conducted this study to determine the impact of antiretroviral therapy during pregnancy on preterm birth and infants small for gestational age. The US-based cohort tracks birth outcomes in HIV-exposed but uninfected infants.

The researchers defined preterm birth as any birth before 37 completed weeks of gestation. They defined spontaneous preterm birth as one that occurred after preterm labor or membrane rupture, without other complications. They defined small for gestational age as birth weight below the 10th percentile for gestational age.

Of the 1869 singleton births recorded, 18.6% were preterm, 10.2% were spontaneous preterm, and 7.3% were small for gestational age. Most mothers, 89%, used triple-antiretroviral combinations during pregnancy.

Statistical analysis adjusted for multiple birth risk factors determined that taking a PI regimen in the first trimester raised chances of preterm birth 55%, while a first-trimester PI regimen raised chances of spontaneous preterm birth 59%.

Taking a PI regimen in the second or third trimester or taking an NNRTI or triple-nucleoside regimen at any time during pregnancy did not affect chances of preterm birth. Triple-antiretroviral therapy during pregnancy did not affect chances of small for gestational age infants.

The investigators conclude that “protease inhibitor use early in pregnancy may be associated with increased risk for prematurity.”

Source: D. Heather Watts, Paige L. Williams, Deborah Kacanek, Raymond Griner, Kenneth Rich, Rohan Hazra, Lynne M. Mofenson, Hermann A. Mendez, and for the Pediatric HIV/AIDS Cohort Study. Combination antiretroviral use and preterm birth. Journal of Infectious Diseases. 2013; 207: 612-621.

For the study abstract

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