Association between Maternal HIV and Adverse Birth Outcomes in the Era of Universal Antiretroviral Therapy in Malawi.

Background: We evaluated the relationship between maternal HIV and birth outcomes in pregnant women.

Setting: Primary health care facilities in Malawi.

Methods: In this prospective cohort study, pregnant women attending their first antenatal care (ANC) visit between 20-36 weeks gestation were categorized by HIV status. Women living with HIV were grouped by HIV viral load at ANC and delivery (detectable >400 copies/mL), CD4+ count at delivery (low <250 cells/mm3), and ART regimen (tenofovir- and efavirenz-based ART). We evaluated low birth weight (LBW, <2500g), preterm birth (PTB, <37 weeks gestation), small for gestational age (SGA, <10th percentile for gestational age), fetal death (pregnancy loss >28 weeks gestation), and perinatal death (<7 days) at delivery using multivariate log-binomial regression.

Results: We enrolled 1208 pregnant women (633 and 575 living with and without HIV, respectively) from 2018-2022. HIV was significantly associated with increased risk of fetal or perinatal death (adjusted risk ratio (aRR) 2.09, 95% CI 1.21, 3.70), LBW (aRR 1.88, 95% CI 1.30, 2.76), and PTB (aRR 1.49, 95% CI ( 1.07, 2.09). The strength of the association with LBW increased with increasing exposure to viral load, with an aRR of 2.35 (1.01, 3.99) for LBW among women with detectable viral loads throughout pregnancy. Low CD4+ count at delivery was associated with LBW. HIV was not significantly associated with SGA. Adverse birth outcomes did not differ by ART regimen.

Conclusion: Maternal HIV infection is a risk factor for adverse birth outcomes and the effect is partially mitigated by viral suppression.