BACKGROUND: Limited data exist on the effectiveness and safety of dolutegravir (DTG)-based antiretroviral therapy (ART) during pregnancy. We compared maternal viral suppression at delivery and infant birth outcomes among women living with HIV in the US who received DTG-based ART versus alternate preferred ART.
METHODS: Women enrolled in the Pediatric HIV/AIDS Cohort Study between 2007-2019 whose initial ART in pregnancy included DTG, atazanavir/ritonavir (ATV/r), darunavir/ritonavir (DRV/r), rilpivirine (RPV), raltegravir (RAL), or elvitegravir/cobicistat (EVG/c) were eligible. Viral suppression (<400 copies/mL) by delivery and adverse birth outcomes (preterm birth [<37 weeks gestation], low birth weight [LBW, <2500 grams], small-for-gestational-age [SGA, <10th percentile for gestational age], any adverse birth outcome) were evaluated. We estimated risk differences for each outcome comparing each alternate ART to DTG separately, adjusting for potential confounders.
RESULTS: 101 women were exposed to DTG as part of their initial ART in pregnancy, 446 to ATV/r, 172 to DRV/r, 232 to RPV, 79 to RAL, and 129 to EVG/c. Women were predominantly Non-Hispanic, Black (66%) and 51% initiated ART prior to conception. Alcohol and illicit drug use was more common among women receiving DTG. CD4 counts were lower and viral loads higher early in pregnancy among women on DRV/r compared to DTG.

DTG-based ART was more effective in achieving viral suppression by the end of pregnancy compared to ATV/r and RAL-based ART (Table). Estimated risks of preterm birth ranged from 11.0% to 18.1% but there were no substantial differences in risks when comparing alternate ART to DTG-based ART. Estimated risks of LBW were increased for ATV/r and RAL-based ART by 6.2% and 8.3%, respectively, compared to DTG-based ART. Estimated risk of SGA was substantially higher for RAL versus DTG-based ART (14.5% vs. 7.5%). Risks of any adverse birth outcome ranged from 20.4% to 27.1% across regimens with a 6.6% higher risk for RAL-based compared to DTG-based ART.

CONCLUSIONS: DTG-based ART is associated with a greater likelihood of viral suppression by delivery compared to alternate ART in pregnancy. Although risks of adverse birth outcomes were similar between regimens, DTG was associated with lower risks for LBW and SGA compared to RAL.