Relationship Between Maternal Economic Vulnerability and Childhood Neurodevelopment at 2 and 5 Years of Life

OBJECTIVE:To assess the relationship between economic vulnerability during pregnancy and childhood neurodevelopment.METHODS:This is a secondary analysis of two parallel multicenter, randomized, controlled trials of administration of levothyroxine to pregnant individuals with subclinical hypothyroidism or hypothyroxinemia in the United States. All participants who delivered a live, nonanomalous neonate and completed the WPPSI-III (Weschler Preschool & Primary Scale of Intelligence) at 5 years of life and the Bayley-III (Bayley Scales of Infant Development) test at 2 years were included. The primary outcome is WPPSI-III score. Secondary outcome included Bayley-III subtest scores. Multivariable analyses were used to assess the relationships between economic vulnerability during the index pregnancy-defined as a household income less than 200% of the estimated federal poverty level, part-time or no employment, and use of government insurance-and the prespecified outcomes. Tests of interaction were performed to assess whether the magnitude of association differed according to whether participants were married or completed more than a high school education. A sensitivity analysis was performed to limit the income criteria for economic vulnerability to household income of less than 100% of the estimated federal poverty level.RESULTS:Of 955 participants who met inclusion criteria, 406 (42.5%) were considered economically vulnerable. In bivariate analysis, the WPPSI-III score and Bayley-III subtest scores were significantly lower among children of the economically vulnerable. For the WPPSI-III, Bayley-III cognitive subtest, and Bayley-III language subtest scores, the associations between economic vulnerability and lower childhood neurodevelopmental scores were primarily seen only among those who were married or completed more than a high school education (P for interaction<.05). A similar pattern was noted when restricting the income criteria for economic vulnerability to less than 100% of the federal poverty level.CONCLUSION:Economic vulnerability during pregnancy is associated with an increased risk of adverse neurodevelopmental outcomes in their children at 2 and 5 years of life, particularly among those who are married or completed more than a high school education.