Impact of Prenatal and/or Postnatal Growth Problems in Low Birth Weight Preterm Infants on School-Age Outcomes: An 8-Year Longitudinal Evaluation

Abstract

OBJECTIVE. The objective of this study was to assess the 8-year growth, cognitive, behavioral status, health status, and academic achievement in low birth weight preterm infants who had failure to thrive only, were small for gestational age only, had failure to thrive plus were small for gestational age, or had normal growth. METHODS. A total of 985 infants received standardized evaluations to age 8; 180 infants met the criteria for failure to thrive between 4 and 36 months' gestational corrected age. The following outcome variables were collected at age 8: growth, cognitive, behavioral status, health status, and academic achievement. Multivariate analyses were performed among the 4 growth groups on all 8-year outcome variables. RESULTS. Children who both were small for gestational age and had failure to thrive were the smallest in all growth variables at age 8, and they also demonstrated the lowest cognitive and academic achievement scores. The children with failure to thrive only were significantly smaller than the children with normal growth in all growth variables and had significantly lower IQ scores. Those who were small for gestational age only did not differ from those with normal growth in any cognitive or academic achievement measures. There were no differences among the 4 groups in behavioral status or general health status. CONCLUSION. Low birth weight preterm infants who develop postnatal growth problems, particularly when associated with prenatal growth problems, demonstrate lower physical size, cognitive scores, and academic achievement at age 8. There does not seem to be an independent affect of small for gestational age status on 8-year cognitive status and academic achievement when postnatal growth is adequate.