Early Postnatal Growth in a Subset of Convalescing Extremely-Low-Birth-Weight Neonates: Approximating the "Index Fetus" Ex Utero.

Objective: The aim of the study was to evaluate whether a subset of noncritically ill, convalescing extremely-low-birth-weight neonates who were managed using a standardized nutritional protocol could achieve the growth rate of the index fetus. We hypothesized that an aggressive nutritional protocol applied to noncritically ill, convalescing premature neonates could achieve the growth rate of the index fetus.

Methods: This was a retrospective review of a subset of 21 premature neonates defined by 4 criteria: inborn or transferred-in within 24 hours of birth, gestational age < 30 weeks and birth weight ≤1000 g, hospitalized >35 postnatal days, and discharged between 34 and 42 weeks postconceptual age. Optimal growth at discharge was defined as weight and head circumference >10th percentile compared with comparable gestational age fetal parameters.

Results: Protein intake of ≥1.4 g · kg · day and energy ≥30 kcal · kg · day were provided as of the first postnatal day. Proteins ≥3 g · kg · day and >80 kcal · kg · day were established ≥10th postnatal day. Birth weight was regained by postnatal day 10 ± 5 day (mean + standard deviation). Nutrition was predominantly enteral (ie, >50% of all calories) after the 11th postnatal day. At discharge, 71% (15/21) by weight and 76% (16/21) by head circumference were >10th percentile. After 30 weeks postconceptual age, the cohort exceeded the weight gain rate (g/wk) of a 10th-percentile fetus.

Conclusions: In a selected subset of noncritically ill, convalescing extremely-low-birth-weight neonates, after a brief period of unavoidable postnatal weight loss and body water adjustment, adequate nutrition from birth can enable a more homeostatic pattern of growth that approximates growth of the index fetus.