Extremely preterm babies are at increased risk of less than optimal neurodevelopment compared with their term-born counterparts. Optimising nutrition is a promising avenue to mitigate the adverse neurodevelopmental consequences of preterm birth. In this narrative review, we summarize current knowledge on how nutrition, and in particular, protein intake, affects neurodevelopment in extremely preterm babies. Observational studies consistently report that higher intravenous and enteral protein intakes are associated with improved growth and possibly neurodevelopment, but differences in methodologies and combinations of intravenous and enteral nutrition strategies make it difficult to determine the effects of each intervention. Unfortunately, there are few randomized controlled trials of nutrition in this population conducted to determine neurodevelopmental outcomes. Substantial variation in reporting of trials, both of nutritional intakes and of outcomes, limits conclusions from meta-analyses. Future studies to determine the effects of nutritional intakes in extremely preterm babies need to be adequately powered to assess neurodevelopmental outcomes separately in boys and girls, and designed to address the many potential confounders which may have clouded research findings to date. The development of minimal reporting sets and core outcome sets for nutrition research will aid future meta-analyses.

Objective To determine whether purposely designed nutritional guidelines for extremely low birthweight (ELBW; birth weight <1000 g) babies result in protein intakes that meet international consensus recommendations, and whether this results in improved growth from birth to discharge. Design A prospective cohort study of nutritional intakes and growth in ELBW babies. Setting A tertiary neonatal intensive care unit in New Zealand. Patients 100 ELBW babies who survived for the first month of life, 50 before the introduction of the guideline (Lo Pro) and 50 after (Hi Pro). Intervention Introduction of a nutritional guideline aimed at increasing protein intakes to meet international consensus recommendations. Main outcome measures Weekly protein intakes over the first month of life and growth until discharge. Results Hi Pro babies had significantly higher protein intakes in the first month of life than Lo Pro babies (mean (SD), 3.8 (0.3) vs 3.3 (0.4) g/kg.day, p<0.0001) and a significantly greater growth velocity (GV) over the first 30 days after regaining birth weight (19.5 (5.0) vs 16.2 (5.4) g/kg.day, p<0.002). Hi Pro babies had a significantly lesser Z-score change between birth and discharge than Lo Pro babies for weight (0.0 (1.2) vs −0.9 (1.1), p=0.001), length (−0.8 (0.8) vs −1.2 (1.1), p=0.02) and head circumference (−0.2 (1.1) vs −1.1 (1.6), p<0.001). Conclusions Simple, standardised nutritional guidelines can result in recommended protein intakes for ELBW babies being achieved and result in increased GV. Downward crossing of centiles between birth and discharge, common in ELBW babies, is significantly reduced for weight, length and head circumference.