Dolutegravir- Versus Efavirenz-Based Treatment in Pregnancy: Impact on Red Blood Cell Folate Concentrations in Pregnant Women and Their Infants

In IMPAACT 2010/VESTED, pregnant women were randomized to initiate dolutegravir (DTG)+emtricitabine (FTC)/tenofovir alafenamide (TAF), DTG+FTC/tenofovir disoproxil fumarate (TDF), or efavirenz (EFV)/FTC/TDF. We assessed red blood cell folate concentrations (RBC-folate) at maternal study entry and delivery, and infant birth. RBC-folate outcomes were: 1) maternal change entry to delivery (trajectory), 2) infant, 3) ratio of infant-to-maternal delivery. Generalized estimating equation models for each log(folate) outcome were fit to estimate adjusted geometric mean ratio (Adj-GMR)/GMR trajectories (Adj-GMRT) of each arm comparison in 340 mothers and 310 infants. Overall, 90% of mothers received folic acid supplements and 78% lived in Africa. At entry, median maternal age was 25 years, gestational age was 22 weeks, CD4 count was 482 cells/mm3 and log10HIV RNA was 3 copies/mL. Entry RBC-folate was similar across arms. Adj-GMRT of maternal folate was 3% higher in the DTG+FTC/TAF versus EFV/FTC/TDF arm (1.03, 95%CI 1.00, 1.06). The DTG+FTC/TAF arm had an 8% lower infant-maternal folate ratio (0.92, 95%CI 0.78, 1.09) versus EFV/FTC/TDF. Results are consistent with no clinically meaningful differences between arms for all RBC-folate outcomes and they suggest that cellular uptake of folate and folate transport to the infant do not differ in pregnant women starting DTG- vs. EFV-based ART.