Comparison Between Early and Late Parenteral Nutrition in Term and Late Preterm Infants

There is a lack of comprehensive evidence on the best timing for initiating parenteral nutrition (PN) in term and late preterm infants. This single-centre, non-blinded, exploratory randomized controlled trial included infants born at or after 34 weeks of gestation and within 28 days old who required PN. Eligible infants were randomly assigned to receive PN on either early PN (on day 1 or 2 of admission) or late PN (on day 6 of admission). The primary outcomes measured were plasma levels of phenylalanine and F2-isoprostanes on days 4 and 8 of admission. Secondary outcomes included amino acid and fatty acid profiles, as well as clinical outcomes.

The results demonstrated the following: 

• The postnatal age at randomization was similar across both groups (2.3 days). 
• By day 4, infants in the early-PN group had significantly higher phenylalanine levels compared to those in the late-PN group (mean 62.9 vs 45.5 µmol/L).
• However, there was no notable difference in phenylalanine levels on day 8.
• F2-isoprostane levels did not show significant differences between groups on either day 4 or day 8.
• Early-PN infants experienced less severe weight growth restriction compared to the late-PN group (change in weight z-score: -0.6 vs -1.0).
• Conversely, the early-PN group had a higher incidence of hyperglycemia (66.7% vs 36.7%).

Thus, the study concluded that the timing of PN initiation did not appear to influence oxidative stress levels in critically ill term and late preterm infants. Further research is needed to explore the implications of elevated plasma phenylalanine levels associated with early PN on clinical outcomes.

Source: Moon K, Mckinnon E, Croft K, Hendrie D, Patole S, Simmer K, Rao S. Early versus late parenteral nutrition in term and late preterm infants: study protocol for a randomised controlled trial. BMC Pediatr. 2022 Aug 30;22(1):514. doi: 10.1186/s12887-022-03569-8. PMID: 36042439; PMCID: PMC9429301.