Pregnancy and Neonatal Outcomes Following Prenatal Exposure to Dolutegravir Background: Birth outcome data with dolutegravir exposure during pregnancy, particularly in the first trimester, are needed. Setting: Data were prospectively collected from the Antiretroviral Pregnancy Registry and European Pregnancy and Paediatric HIV Cohort Collaboration. Methods: We reviewed 2 large, independent antiretroviral pregnancy registries to assess birth outcomes associated with maternal dolutegravir treatment during pregnancy. Results: Of 265 pregnancies reported to the Antiretroviral Pregnancy Registry, initial exposure to dolutegravir occurred at conception or first trimester in 173 pregnancies and during the second or third trimester in 92 pregnancies. There were 246 (92.8%) live births resulting in 255 neonates (9 twins), 6 (2.3%) induced abortions, 11 (4.2%) spontaneous abortions, and 2 (0.8%) stillbirths. Birth defects occurred in 7 (2.7%) of 255 live-born neonates, 5 (3.1%) of 162 (includes 6 twins) with conception/first-trimester exposure. Of 101 pregnancies reported to the European Pregnancy and Paediatric HIV Cohort Collaboration, outcomes were available for 84 pregnancies (16 continuing to term and 1 lost to follow-up). There were 81 live births (80 with known initial dolutegravir exposure at conception or first, second, and third trimesters in 42, 21, and 17 live births, respectively), 1 stillbirth (second-trimester exposure), 1 induced abortion (first-trimester exposure), and 1 spontaneous abortion (first-trimester exposure), respectively. Birth defects occurred in 4 live births (4.9%; 95% confidence interval: 1.4 to 12.2), 3 of 42 (7.1%) with exposure at conception or first trimester. Conclusions: Our findings are reassuring regarding dolutegravir treatment of HIV infection during pregnancy but remain inconclusive because of small sample sizes.