Abstract
Background: Studies of small for gestational age (SGA) birth and subsequent childhood cognitive outcomes are inconsistent. Few studies have assessed whether effects varied by socioeconomic status (SES).
Objective: To assess child cognitive and behavioral outcomes according to SGA and severe SGA (<10th and <5th percentiles) and SES.
Methods: We followed 474 infants initially selected for a case-control study assessing SGA vs. appropriate-for-gestational age (AGA). The infants were born at two hospitals: a public hospital serving a low-income, African-American population and a private hospital serving a predominantly white, middle-class population. At age 54 months, a psychologist administered the Differential Abilities Scales (DAS), and Vineland Adaptive Behavior Scales (VABS). The mother completed the Child Behavior Checklist (CBCL). Associations were analyzed using multiple linear regression.
Results: Among AGA children, the mean DAS score was >1 standard deviation lower for children born at the public vs. the private hospital (75.2 vs. 95.7 among boys; 76.3 vs. 101.8 among girls). Being SGA had a weaker effect on DAS scores, overall. Severe SGA had a significant effect on DAS scores of children born at the private hospital (average reduction 8.0±2.5 points), but not on children born at the public hospital (average reduction 1.1±2.2 points). In the latter group, severe SGA was associated with a lower VABS score (average reduction 9.2±2.5 points).
Conclusions: Poor fetal growth influences neurodevelopment, but this influence is modified by postnatal environment. Adverse effects associated with low SES might mask or attenuate associations between prenatal exposures and developmental outcomes in some populations.
©2011 by Walter de Gruyter Berlin Boston
