Area Poverty and Adverse Birth Outcomes: An Opportunity for Quality Improvement.

Objective: To evaluate the association between area poverty and adverse birth outcomes in the diverse birthing population of a large health system.

Methods: This was a retrospective cohort study using electronic health record and hospital administrative data for pregnant people at nine hospitals within a large health system in the Chicago metropolitan area from 2018 to 2023. Patient addresses were geocoded and categorized by Census tract area percent poor households. Unadjusted and adjusted Poisson regression models, controlling for individual-level risk factors, evaluated the independent association between area poverty and birth outcomes to determine the degree to which this association is attenuated by the inclusion of individual-level factors in the model.

Results: The study included 85,025 pregnant people. Area poverty was associated with sociodemographic factors, including young age, non-Hispanic Black race, Hispanic ethnicity, Medicaid insurance coverage, higher parity, and several comorbid conditions. Area poverty was associated with adverse birth outcomes and demonstrated a gradient effect with increasing area poverty in bivariable analyses. In unadjusted regression analyses, residence in areas with 5.0% or more poverty was associated with severe maternal morbidity, preterm birth, and low birth weight, and residence in areas with 8.0% or higher poverty was associated with neonatal intensive care unit admission. Although these associations persisted in multivariable analysis for severe maternal morbidity and neonatal intensive care unit admission, the associations with preterm birth and low birth weight persisted only for individuals residing in areas of 12.0% or higher poverty when controlling for individual-level risk factors.

Conclusion: Area poverty was associated with adverse birth outcomes in this birthing population even when controlling for individual-level risk factors, highlighting the need for system- and community-level quality-improvement interventions.