Maternal Racial Differences and Socioeconomic Status in Preterm Infant Neurodevelopment, Feeding, and Growth

Women from diverse socioeconomic status (SES) face a higher risk of preterm birth, increasing their infants' vulnerability to neurodevelopmental and other health disorders; however, the predictive role of maternal ZIP code level SES in these outcomes remains underexplored.

To investigate the associations between maternal racial disparity, ZIP code-level SES, and infant breastfeeding, growth, and neurodevelopmental trajectories.

In this cohort study, preterm infants were recruited from two Connecticut neonatal intensive care units (NICUs). Infant demographic data, feeding regimens, and growth during the NICU stay were documented. Neurodevelopmental outcomes were assessed using the NICU Neonatal Neurobehavioral Scale, the Bayley scale of infant and toddler development (3rd ed.), and the Brief Infant Toddler Social Emotional Assessment. To compare SES differences between infants born to Black and White mothers, both t -tests and Wilcoxon tests were conducted. We used XGBoost to analyze infant health outcomes and SHapley Additive exPlanations (SHAP) values to identify SES-related risk factors associated with feeding, growth during NICU stay, and neurodevelopmental outcomes up to 2 years of age.

In total, 181 preterm infants from eight ZIP code areas were included in the study. The majority of infants were born to mothers who were White and non-Hispanic. Compared with infants born to White mothers, those born to Black mothers had younger birth gestational age (GA), lower birth weights, shorter birth lengths, smaller head circumferences, and higher Score of Neonatal Acute Physiology with Perinatal Extension-II (SNAPPE-II), with all differences being statistically significant. Compared with White mothers, Black mothers were younger, single, and less educated. Black mothers also had lower median household incomes, larger average family sizes, and higher levels of poverty compared with White mothers. Based on SHAP values, the risk factors predicting infants' feeding, growth, and neurodevelopment are ranked as follows: birth weight, birth GA, SNAPPE-II score, average family size, maternal age, median household income, poverty level, and school enrollment.

Maternal racial disparity and SES serve as predictors of feeding, growth, and neurodevelopmental outcomes in preterm infants. Understanding these associations can inform health care strategies for vulnerable preterm populations to improve long-term health outcomes.