(92) Epidemiology, Trends, and Racial Disparities in Infant Mortality Attributable to Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a significant cause of morbidity and mortality in newborns. In the United States (US), shifts in gestational age distribution have led to increased preterm and early-term births, while full-term and late-term births have declined. This has decreased the incidence of meconium aspiration syndrome (MAS), a known cause of PH, but the impact on PH mortality is unclear.

Objectives: This study evaluated the epidemiology, temporal trends, and racial/ethnic disparities in infant mortality from PH among U.S. newborns between 2007 and 2022.

Design/Methods: This was a retrospective cross-sectional review conducted using CDC-linked birth and infant death data. Included were infants born to U.S. resident mothers who died in their first year with PH listed as the underlying cause of death (ICD-10 codes P29.3, I27.0, I27.2). Records with < 20 deaths were excluded per CDC guidelines. The outcome included infant mortality rate (IMR), defined per 1,000 live births, stratified by race/ethnicity (non-Hispanic Black [NHB], non-Hispanic White [NHW], Hispanic), gestational age (GA), gender, and timing of death. Trends in IMR due to MAS and congenital diaphragmatic hernia were also analyzed. Descriptive statistics, Mann-Whitney U or ANOVA, and linear regression were used, with significance at p< 0.05.

Results: Of 62,699,904 live births, 2,702 infant deaths were attributed to PH (IMR 0.04/1,000). Deaths by race included NHW (43%), NHB (31%), and Hispanic (23%). Most deaths (53.7%) occurred within 28 days: 6.9% on day 1, 24.6% between days 1–6, and 22.2% between days 7–27. NHB infants had a significantly higher IMR (0.09) than NHW (0.04) and Hispanic (0.03) infants (p=0.001). The NHB-to-NHW IMR ratio remained stable at 3 across the study period. IMR was inversely related to GA—highest at 22–24 weeks (2.7) and lowest at ≥37 weeks (0.02). There were no significant gender differences. No significant trend in overall PH-related IMR was observed over time. Sensitivity analyses showed no change in IMR due to MAS or congenital diaphragmatic hernia.

Conclusions: While infant mortality due to PH remains low and stable over time, NHB infants continue to face a disproportionately higher risk. These persistent racial disparities highlight the urgent need to address underlying systemic and healthcare-related factors. Additionally, understanding the timing of death offers valuable insights for improving PH outcomes in neonates.