Environmental roots of neonatal health: how social and structural exposures shape early-life outcomes

Neonatal health in the United States is influenced by a combination of biological, social, environmental, nutritional, and healthcare factors, with structural exposures-such as historical redlining, air pollution, and neighborhood disadvantages-associated with differences in perinatal outcomes. This review synthesizes nearly a century of multidisciplinary evidence linking adverse exposures in utero to persistent disparities in neonatal survival and neurodevelopment. We outline biological mechanisms, notably stress-mediated alterations of the fetal HPA axis and epigenetic changes, that may mediate the effects of social and environmental adversity before birth. Historical and contemporary data highlight the enduring impact of discriminatory policies on neonatal outcomes, emphasizing how structural racism and environmental injustice have been linked to higher rates of preterm birth and low birth weight. In addition, disparities in prenatal care access, food insecurity, infection, and inflammatory conditions represent important pathways through which social conditions may affect fetal growth and neonatal outcomes. Advances in exposomics and biomarker science now allow more precise measurement of early-life exposures, while place-based policy interventions, including urban greening and zoning reform, show promise in mitigating harm. Integrating these scientific and policy approaches is essential to disrupt intergenerational cycles of risk and advance perinatal equity. Bridging socioeconomics, environmental, and biological research offers a path forward to ensuring that all infants- regardless of background- have the opportunity for a healthy start. IMPACT: Review linking social and structural exposures, especially in redlining, air pollution, and environmental injustice disparities in neonatal survival and neurodevelopment. Highlights novel advances in exposomics and place-based policy interventions that target root causes and offer promising strategies to improve perinatal equity. Provides an integrated biological, clinical, and policy framework for disrupting intergenerational cycles of risk and advancing neonatal health equity.