Growth of Very Low Birth Weight Infants to Age 20 Years

Abstract

Objective. Intrauterine and neonatal growth failure of very low birth weight (VLBW; 30) for VLBW males were 7% compared with 15% for controls and for VLBW females 15% compared with 18% for controls. Age of menarche was 12.4 years for VLBW females and 12.3 years for controls. Nineteen (18%) male and 20 (22%) female VLBW subjects were born small for gestational age (SGA; weight less than −2 standard deviation for gestational age). At 20 years, significantly more SGA than appropriate for gestational age VLBW males remained subnormal (less than −2 standard deviation) in weight (32% vs 6%) and height (21% vs 4%), whereas rates of subnormal growth did not differ significantly between SGA and appropriate for gestational age females (weight 5% vs 1%, height 0% vs 7%). Predictor variables included in the multivariate analyses of 20-year growth attainment were maternal education and height, race, birth weight z score (a measure of intrauterine growth failure), neonatal hospital stay (a measure of neonatal illness), and chronic illness at 20 years. Twenty-year weight was predicted by black race and chronic illness among females. Twenty-year height was predicted by maternal height and birth weight z score among both males and females and by duration of neonatal hospital stay among males only. In a separate model, when we examined the effect of being SGA at birth instead of the effect of birth weight z score, SGA birth was predictive of 20-year height among males but not among females. Conclusions. VLBW females catch up in growth by 20 years of age whereas VLBW males remain significantly shorter and lighter than controls. Since catch-up growth may be associated with metabolic and cardiovascular risk later in life, these findings may have implications for the future adult health of VLBW survivors.