An Evaluation of Perinatal Human Immunodeficiency Virus Transmissions in New York State, 2007-2020

To evaluate predictors of perinatal human immunodeficiency virus (HIV) transmission and birthing parent unsuppressed HIV viral load proximate to delivery in New York State.

This was a population-based, retrospective cohort study of perinatal HIV transmission from 2007 to 2020 using data from the New York State Department of Health's Wadsworth Center, HIV Surveillance System, and medical record abstraction. Birthing parents living with HIV and their live-born infants were included. Multivariable models estimated the association between predictors and perinatal HIV transmission with adjusted odds ratios (AORs) and 95% CIs reported. Risk ratios (RRs) were calculated to evaluate predictors of an unsuppressed viral load before (closest test results) delivery.

Of 5,722 birthing parent-infant dyads included in analysis, perinatal transmission was presumed or confirmed for 44 infants (0.77%). In multivariable analyses, an unsuppressed viral load at the test closest to delivery predicted perinatal HIV transmission (AOR 10.47, 95% CI, 4.35-27.80). The strongest predictors of an unsuppressed viral load in multivariable analyses were documented illicit substance use during pregnancy (adjusted RR 1.79, 95% CI, 1.57-2.03), nonuse of prenatal antiretroviral therapy during pregnancy (adjusted RR 2.91, 95% CI, 2.46-3.45), and later initiation of prenatal care (second compared with first trimester: adjusted RR 1.34, 95% CI, 1.17-1.54; third trimester: adjusted RR 1.81, 95% CI, 1.51-2.18).

Rates of perinatal HIV transmission were low in this retrospective cohort study. However, unsuppressed viral load proximate to delivery remains a strong predictor for perinatal transmission, providing insight into priorities for addressing rare but ongoing perinatal HIV transmission.