2.4. Sociodemographic and Clinical Characteristic Variables
Maternal race was self-reported via questionnaire and was defined as African American, non-Hispanic Caucasian, or Hispanic. The extent of maternal education was dichotomized as (1) less than college or (2) some college or greater. Marital status was defined as married or unmarried, which included single, divorced, or widowed. Insurance status was defined as private, Medicaid, or none. The feeding status of the infants was dichotomized as (1) exclusively breastfed or (2) exclusively formula-fed or mixed formula-breastfed. Small for gestational age (SGA) was defined using Fenton growth curves [