This was a retrospective analysis (2009-2021) of service utilization, prescription claims, and ICD codes from a database sampling ~15-20% of individuals covered by Medicaid in participating states.  Investigators identified outpatient use of antiretroviral medications using national drug codes over the initial 42 days of life for various postnatal HIV prophylaxis combinations: zidovudine alone, zidovudine plus nevirapine, or zidovudine plus lamivudine and either nevirapine or raltegravir, reflecting shifts in HHS recommendations over the study period.  Overall, 2,304 infants received postnatal prophylaxis in this sample.  Use of dual- and triple-drug regimens increased over time, such that dual-drug prophylaxis was used in up to 5-10% of infants in the early to mid-2010s and triple-drug prophylaxis containing nevirapine became increasingly common in the late 2010s (and was more commonly used than dual combinations by 2018).  By the end of the study period, the rate of raltegravir use as the third agent approached the rate of nevirapine use as the third agent.  The rate of zidovudine single-drug prophylaxis use declined to 71.7% by 2021.  52 infants were diagnosed with HIV within the first year of life among the sample, with 36 out of 52 (69.2%) diagnosed between 42 days and one year of life.  Of these infants, 27 did not have evidence of any receipt of postnatal prophylaxis.

Although this analysis reflects a limited sample of HIV-exposed infants delivered in the U.S. between 2009-2021, results suggest that clinician practice has evolved over time in response to HHS recommendation changes regarding antiretroviral management of infants with utero or intrapartum exposure to HIV.  Overall prevalence of perinatal transmissions was low, however the proportion of infants diagnosed with HIV beyond the immediate postnatal period is of concern – along with the finding that most of these infants had not received any prophylaxis (suggesting that maternal infection had not been identified or effectively treated).  Further, by 2021 approximately one-third of infants received triple-drug prophylaxis regimens, possibly reflecting more “high risk” exposure scenarios over time.  These observations highlight the importance of early and regular HIV screening and incorporation of other effective HIV prevention interventions (e.g., PrEP/PEP and rapid ART initiation) during pregnancy.