Extra Protein for Preemies Boosts NICU Growth, but Does it Last?

Pediatrician listening to a laughing infant’s chest with a stethoscope

When it comes to extremely preterm (EPT) infants born between 25 and 28 weeks of gestation, nutrition is more than a growth issue; it’s a survival strategy. Early protein intake in the NICU has been linked to better weight gain, lean mass, and even potential neurodevelopmental benefits.

Our new study followed EPT infants who had received protein-enriched human milk diets in the NICU, tracking their growth and neurodevelopment through about two years of corrected age.

The Study in Brief

This was a secondary analysis of a randomized, masked clinical trial involving 56 preterm infants. After postnatal day 14, infants were randomized to one of two diets:

High protein: Standard fortified milk plus extensively hydrolyzed protein supplement
Standard protein: Standard fortified milk without extra protein

We looked at moderate to severe neurodevelopmental impairment (NDI) or death as the primary outcome, plus growth measures at two years corrected age.

The Results

NDI or death: No meaningful difference between the two groups (43% in standard protein vs. 42% in high protein).
Bayley developmental scores: Similar cognitive, language, and motor results in both groups.
Growth: By two years, weight, length, and head circumference were similar regardless of early protein supplementation.

What It Means

The high-protein group did show better weight and FFM z-scores in the NICU (as seen in the original trial), but these benefits faded after discharge. The takeaway? While extra protein may help in the short term, those gains may not last without continued nutrition strategies after leaving the hospital.

The Bigger Picture

This study highlights a critical challenge in neonatal nutrition: bridging the gap between short-term hospital benefits and long-term developmental outcomes. Early protein helps preemies grow stronger in the NICU—but without a post-discharge nutrition plan, those gains can disappear.

Bottom Line:
Extra protein in fortified human milk improved growth in the NICU, but it didn’t translate into lasting neurodevelopmental or growth advantages at two years. Future research needs to focus on sustaining early nutritional gains after discharge to truly change long-term outcomes for extremely preterm infants.