Viral load, ART regimen predict mortality in infants born to mothers living with HIV

Several infants born to mothers living with HIV die within 50 weeks, and some of the factors that may contribute to infant death include lower maternal CD4 count, higher viral load, and maternal antiretroviral (ART) regimen, among others, suggests a study presented at CROI 2026.

“Most infant deaths occurred in the first month of life,” said lead author Dr Violet Korutaro, Baylor College of Medicine Children’s Foundation, Kampala, Uganda. “In addition to preterm birth and low birth weight (LBW), maternal ART regimen and high viral load had substantial associations with infant mortality, highlighting the need for good maternal and newborn care.”

Korutaro and colleagues conducted an exploratory analysis of the IMPAACT 2010 (VESTED) trial, which compared dolutegravir (DTG) plus emtricitabine/tenofovir alafenamide fumarate (FTC/TAF), DTG plus FTC/tenofovir disoproxil fumarate (TDF), and efavirenz (EFV)/FTC/TDF initiated during pregnancy among 643 women in nine countries.

“Previous analyses showed superior virologic efficacy and pregnancy outcomes with DTG-based compared with EFV-based ART,” according to the authors.

In the current analysis, Korutaro and her team used the Kaplan‒Meier method to estimate the probability of death among liveborn infants through 50 weeks after birth, overall and by randomized maternal ART regimen.

They also explored potential maternal (ie, baseline gestational age, CD4 count, and viral load at enrolment; and antepartum weight gain, folate, and HbA1c) and infant risk factors (ie, preterm birth, LBW, small-for-gestational-age [SGA], major congenital anomaly, and HIV infection) for infant mortality in univariable log-binomial models.

Infant deaths

Overall, 640 deliveries were identified, of which 23 (3.6 percent) were stillborn and excluded from the analysis (four in the EFV/FTC/TDF arm, eight in the DTG+FTC/TAF arm, and 11 in the DTG/FTC/TDF arm). Among liveborn infants, 20 (3.3 percent) died by 50 weeks, with most deaths (n=15, 75 percent) occurring within the first 28 days. [CROI 2026, abstract 827]

Notably, mortality rates were significantly higher among infants with exposure to EFV/FTC/TDF (6.9 percent) than those exposed to DTG+FTC/TAF (1.0 percent; difference 5.9 percent, 95 percent confidence interval [CI], 2.2‒9.7) and to DTG+FTC/TDF (2.0 percent; difference, 4.9 percent, 95 percent CI, 0.9‒8.9).

Furthermore, mortality was increased for infants of mothers with lower baseline CD4 count (<500 vs ≥500 cells/mm³; risk ratio [RR], 2.34, 95 percent CI, 0.86‒6.35) and higher maternal viral load at delivery (>1,000 vs <50 copies/mL; RR, 4.5, 95 percent CI, 1.2‒17.5).

The following factors also significantly contributed to infant mortality: preterm birth (RR, 6.6, 95 percent CI, 2.8‒15.4), LBW (RR, 6.8, 95 percent CI, 2.7‒17.2), SGA (RR, 2.8, 95 percent CI, 1.1‒7.3), congenital anomalies (RR, 8.1, 95 percent CI, 1.4‒46.6), and infant HIV infection (RR, 8.1, 95 percent CI, 1.4‒46.6).

On the other hand, factors such as maternal viral load at enrolment, maternal age, RBC folate, HbA1c, or antepartum weight change did not significantly predict infant death.

“[These findings] highlight the importance of optimized maternal ART regimens, viral suppression, and preserved CD4 cell count in pregnancy, and targeted neonatal care to reduce infant mortality,” Korutaro said.