Perinatal and Socioeconomic Risk Factors for Variable and Persistent Cognitive Delay at 24 and 48 Months of Age in a National Sample

Marianne M. Hillemeier, Pennsylvania State University
Paul Morgan, Pennsylvania State University
George Farkas, University of California, Irvine
Steven Maczuga, Pennsylvania State University

This paper analyzes perinatal and sociodemographic risks for cognitive delay at 24 and 48 months using data from the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B) (n=7,220). Of 976 children delayed at 24 months, 236 (24.2%) remained delayed by 48 months; 493 (7.9%) of 6,244 children not delayed at 24 months exhibited delay at 48 months. Low birthweight increased delay risk at 24, but not 48 months. Low maternal education had a strongly increasing effect (OR=2.3 at 24 months, 13.7 at 48 months), as did low income (OR=1.4 at 24 months, 7.0 at 48 months). Among children delayed at 24 months, low maternal education predicted delay even more strongly at 48 months (OR=30.5). Although gestational factors including low birthweight increase cognitive delay risk at 24 months, low maternal education and family income are more prevalent and are much stronger predictors of persistent and emerging delay between 24 and 48 months.