The safety of a dolutegravir (DTG)-based antiretroviral treatment (ART) regimen for pregnancy and birth outcomes in Ethiopia: evidence from multicenter cohort study.

Background: A dolutegravir (DTG)-based antiretroviral regimen has been rolled out for pregnant women in low- and middle-income countries since 2020. However, available safety data are limited to a few clinical trials and observational studies. Hence, we present real-world pregnancy and birth outcome safety data from a large sample multicenter cohort study in Ethiopia.

Methods: A retrospective cohort study was conducted in fourteen hospitals across Ethiopia from 2017 to 2022. HIV-infected pregnant women were followed from the date of prevention of mother-to-child transmission (PMTCT) care enrolment until the infant was 6-8 weeks old. The primary safety outcome was a composite of adverse pregnancy events comprising spontaneous abortion, intrauterine fetal death (IUFD) before onset of labor, preterm birth, and maternal death. Additionally, a composite adverse birth outcome was assessed, comprising intrapartum fetal demise, low birth weight, and neonatal death. Finally, a composite of adverse pregnancy or birth outcome was also investigated. The exposure of interest was the antiretroviral treatment (ART) regimen used during pregnancy for PMTCT of HIV.

Results: During the study period, 2643 women were enrolled in routine PMTCT care. However, 2490 (92.2%) participants were eligible for the study. A total of 136/1724 (7.9%, 95% CI: 6.7-9.3%) women experienced adverse pregnancy outcomes. Fewer women in the DTG-based group (5.4%, 95% CI: 3.7-7.5%) had adverse pregnancy outcomes than in the Efavirenz (EFV)-based group (8.3%, 95% CI: 6.6-10.3%), P = 0.004. After controlling for baseline differences, the DTG group had a 43% lower risk of adverse pregnancy outcomes (adjusted odd ratio (AOR), 0.57; 95% CI, 0.32-0.96%) and a 53% lower risk of preterm birth (AOR, 0.47; 95% CI, 0.22-0.98%) compared to the EFV group. A total of 103/1616 (6.4%, 95% CI: 5.2-7.7%) women had adverse birth outcomes. Although the difference was not statistically significant, fewer women in the DTG group (30/548; 5.5%, 95% CI: 3.7-7.7%) than in the EFV group (57/830; 6.9%, 95% CI: 5.2-8.8%) had adverse birth outcomes.

Conclusions: In this study, we observed that DTG-based regimens were associated with better pregnancy and birth outcome safety profiles, reaffirming the WHO recommendation. However, a prospective study is recommended to assess uncaptured maternal and perinatal adverse outcomes, such as congenital abnormalities, and infant growth and neurocognitive development.