317 Comparison of Growth of ELBW Survivors and NBW From Birth to Young Adulthood

Objective: To compare the final growth attainment of extremely low birthweight (ELBW) and normal birthweight (NBW) peers at young adulthood (YA), and to demonstrate differences in the pattern of growth from birth. Design/Methods: Longitudinal regional cohort study of a population-based cohort of 166 ELBW survivors, 501-1000g BW (1977–82), and 145 sociodemographically matched NBW reference group. Weight and length z-scores were computed at birth (Kramer 2001), and at age 3, 8, teen and YA (CDC 2000); BMI was calculated at age 3, 8, teen and YA. Gender-specific longitudinal growth measures were examined.Results: At YA 147/166 (89%) ELBW survivors and 131/145 (90%) NBW were assessed at a mean age of 23.3 (SD 1.2) and 23.7 (SD 1.1) years; 23.5% ELBW were SGA (<10th percentile) and 27% had neurosensory impairments (NSI). Weight for age z-scores for ELBW showed a decline until age 3, with subsequent significant catch-up between age 8 and adolescence, particularly for females, and a further slower catch-up to YA. In terms of height for age z-scores, both sexes of ELBW were disadvantaged at every age compared to NBW. Differences between groups remained significant even after exclusion of NSI, except for YA male weight. The BMI for ELBW showed a sustained incline from 3 to YA, where both sexes are now comparable to their peers. Using the GLM model, ELBW were significantly shorter relative to the NBW peers and their expected mid-parental height.Conclusions: ELBW children show growth failure during infancy followed by accelerated weight gain and crossing of BMI percentiles at adolescence − a pattern that may increase risk of insulin resistance and coronary heart disease. However, BMI (also a coronary risk factor) was slightly lower in ELBW at YA.