Growth and development during the first year in a cohort of low income term-born American children.

Abstract

Background: Infants born small for gestational age (SGA) are at risk for poor postnatal growth and development. This study evaluates biologic and environmental determinants of outcome during the first year of life in a cohort of low income term-born American infants.

Methods: Seven hundred and seventeen of 949 (76%) singleton births to women followed from early pregnancy were studied over their first year of life and measures of growth, home environment, physical and cognitive development were obtained. Infants were categorized as SGA or non-SGA based on birthweight < 15th percentile for gestational age. SGA and non-SGA children's outcomes were analyzed by race, gender and symmetry.

Results: SGA infants were demographically similar to non-SGA infants but significantly lower in mean maternal height, weight and education. Birthweight, crownheel length and head circumference were all significantly smaller in SGA infants. By age 1 year, the SGA children were still shorter, lighter and had smaller head circumferences than the non-SGA children though their rate of growth during the first year was significantly greater for length and head circumference. Cognitive functioning as measured by the Bayley Scales of Infant Development and the Fagan Test of Infant Intelligence did not differ significantly except for a lower Bayley Psychomotor Development Index (PDI) in SGA infants. Since most of these children live in economically disadvantaged households, any negative consequences of poor intrauterine growth may be influenced by postnatal environment and longer term follow-up will be necessary to assess this relationship.