First-week protein and energy intakes are associated with 18-month developmental outcomes in extremely low birth weight infants.

Objective: We sought to evaluate the association between early protein and energy intake and neurodevelopment and growth of extremely low birth weight (<1000 g) infants.

Study Design: Daily protein and energy intakes were collected by chart review for the first 4 weeks of life on 148 extremely low birth weight survivors. A total of 124 infants (84%) returned for evaluation at 18 months' corrected age. Bivariate analysis tested correlations between weekly protein or energy intakes and Bayley Mental Development Index, Psychomotor Development Index, or growth at 18 months. Separate regression models evaluated contributions of protein (grams per kilogram per day) and energy intake (kilojoules per kilogram per day) to the Mental Development Index, Psychomotor Development Index, and growth, while controlling for known confounders.

Results: After adjusting for confounding variables, week 1 energy and protein intakes were each independently associated with the Mental Development Index. During week 1, every 42 kJ (10 kcal)/kg per day were associated with a 4.6-point increase in the Mental Development Index and each gram per kilogram per day in protein intake with an 8.2-point increase in the Mental Development Index; higher protein intake was also associated with lower likelihood of length <10th percentile.

Conclusions: Increased first-week protein and energy intakes are associated with higher Mental Development Index scores and lower likelihood of length growth restrictions at 18 months in extremely low birth weight infants. Emphasis should be placed on providing more optimal protein and energy during this first week.