Birth weight and childhood growth.

Most previous studies of the relationship between birth weight and childhood growth have concentrated on the growth of low birth weight infants. To examine this relationship throughout the full range of birth weights, growth data for children less than 5 years of age from the Tennessee Special Supplemental Food Program for Women, Infants, and Children linked to birth certificate records for 1975 to 1985 were used. Growth status was compared for 500-g birth weight categories from 1,000 g to 4,999 g using mean Z scores and the percentage of children more than 2 SD above or less than 2 SD below the median for height for age, weight for age, and weight for height. Infants with lower birth weights were likely to remain shorter and lighter throughout childhood, especially those who were intrauterine growth retarded rather than premature. Conversely, those infants with higher birth weights were likely to remain taller and heavier and to have a higher risk of obesity. Birth weight is a strong predictor of weight and height in early childhood, not only for low birth weight children but also for those of normal and high birth weight.