Neonatalogist Valley Children's Healthcare Madera, California
Disclosure(s):
Navya Katragadda, DO, MBA: I do not have any relevant financial / non-financial relationships with any proprietary interests.
Background: The causes and timing of death in preterm infants born at 22-23 weeks gestational age (GA) have not been extensively studied. Also, traditional births-based approach to evaluating racial differences in neonatal mortality are fraught with stratification bias.
Objectives: We examined the causes and timing of death and racial/ethnic differences in a modern cohort of periviable infants born at 22-23 weeks of gestational age in the United States with the fetuses-at-risk approach (FAR).
Design/Methods: We conducted a population-based retrospective cohort study of the linked birth/infant death records from the CDC from 2019 to 2022. We included infants born at 22-23 weeks GA with birth weight < 750 grams and excluded infants without GA or birthweight. The causes of death [bacterial/fungal sepsis, necrotizing enterocolitis (NEC), acute and respiratory failure including respiratory distress and bronchopulmonary dysplasia, and intraventricular hemorrhage (IVH)] were identified with ICD-10 codes. The outcome was the causes and timing of death, overall, and stratified by race/ethnicity. The outcome measure was the infant mortality rate (IMR) per 10,000 FAR. IMR was calculated by dividing the number of deaths at each GA by the number of livebirths and fetal deaths at that GA and beyond multiplied by 10,000. Time of death was classified as < 1 hour, 1-23 hours, 1-7 days, 8-27 days, and 28-364 days of age. Race was categorized as Non-Hispanic Black (NHB), Non-Hispanic White (NHW), and Hispanic.
Results: Among 14.7 million fetuses-at-risk (fetal deaths: 67,432; livebirths: 14.6 million), 10,272 born at 22-23 weeks died in the first year (IMR 7.0). For all infants and all races/ethnicity, the IMR peaked at 1-23 hours of life and then decreased to the lowest rate at 28-364 days of age (Figure 1). The IMR was highest in NHB (15.3) compared to NHW (7.5) and Hispanic (6.6) infants (P < 0l.001) and the NHB IMR was significantly higher at every time point. Overall, the causes of death varied with time (Figure 2). Their causes and timing of death also varied with race/ethnicity. Death from NEC and sepsis peaked at 7-27 days overall across all racial groups but the IMR was highest in NHB infants. Death from respiratory causes and IVH peaked at 1-6 days of life and was highest in NHB infants.
Conclusions: The causes of death among periviable preterm infants born at 22-23 weeks varied with time. There were significant racial/ethnic disparities in the causes and timing death. These findings can inform future research to improve outcomes.
