Background: Achieving adequate nutrition in preterm infants is challenging. The post-discharge period may be critical for influencing growth and cognitive outcomes. We studied the effects of post-discharge nutrition on childhood cognition.
Methods: Preterm-born children were randomized at ~36 weeks corrected age (CGA) to either preterm formula (PTF) or term formula (TF) until 6 months, or PTF until 40 weeks CGA, then TF until 6 months (crossover group). Childhood cognition was assessed using the short form Wechsler Intelligence Scale for Children III, allowing computation of full-scale intelligence quotient (FSIQ) and four-factor index scores; verbal comprehension, freedom from distractibility (FDI), perceptual organization (POI), and processing speed (PSI).
Results: Ninety-two children were recruited (mean 10.1 years). FSIQ did not differ by group. PTF-fed children had 10-point higher PSI (p = 0.03) compared to crossover. Faster weight gain from term to 12 weeks CGA was associated with 5-point higher FSIQ (p = 0.02) and four-point higher POI (p = 0.04). Infant head growth was positively associated with FSIQ (+3.8 points, p = 0.04) and FDI (+6 points, p = 0.003).
Conclusions: While there is no long-term impact of post-discharge macronutrient enrichment on childhood cognition, greater weight and head growth in specific epochs is associated with better outcomes. Further studies are needed to determine optimal early diet in preterm infants.
Impact: Achieving adequate nutrient intakes in preterm infants before and after hospital discharge is challenging. Nutrient intakes prior to discharge affect later cognitive and metabolic outcomes. Follow-up of a randomized controlled trial shows no cognitive benefit in later childhood from a more nutrient-dense formula compared to standard formula after hospital discharge. Growth in the first year of life is strongly correlated with childhood cognition and emphasizes the importance of nutrition in early life.