Impact of Early and High Amino Acid Supplementation on ELBW Infants at 2 Years

Objective: The aim of the present study was to examine the effects of early and high intravenous (IV) amino acid (AA) supplementation on growth, health, and neurodevelopment of extremely-low-birth-weight (ELBW) infants throughout their first 2 years of life. Methods: Infants were prospectively randomized in a double-masked fashion and treated for 7 days with either IV AA starting at 0.5 g . kg(-1) . day(-1) and increased by 0.5 g . kg(-1) every day to 3 g . kg(-1) . day(-1) or starting at 2g . kg(-1) . day(-1) of IV AA and advanced by 1 g . kg(-1) every day to 4g . kg(-1) . day(-1). Plasma AA concentrations were determined by reverse-phase high-performance liquid chromatography. Survivors were longitudinally assessed with Bayley II Scales of Infant Development and physical, social, and global health. Results: Forty-three of 51 survivors were studied. Mental Developmental Index (MDI) and Psychomotor Developmental Index were similar between groups; however, the early and high AA group had a lower MDI at 18 months. This difference disappeared at 2 years of age. The early and high AA group z score means for weight, length, and head circumferences were significantly lower than the standard AA group at most visits. Cumulative and single plasma AA concentrations correlated negatively with MDI and postnatal growth. Conclusions: ELBW infants who received early and high IV AA during the first week of life were associated with poor overall growth at 2 years.