Risk Factors for Postnatal Growth Faltering and Undernutrition at Discharge in Very Preterm Infants: A Retrospective Study Applying the ESPGHAN Consensus Definitions.

BACKGROUND

Postnatal growth failure in very preterm infants remains a major concern in neonatal care and clinical management is complicated by the lack of a standardized definition. This study aims to identify risk factors for growth faltering (GF) and undernutrition (UN) at hospital discharge, defined according to the latest consensus definitions established by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN).

METHODS

We conducted a retrospective observational study of 416 preterm infants (gestational age < 32 weeks and/or birth weight < 1500 g). Growth was monitored using the Intergrowth 21st standards. In line with ESPGHAN criteria, GF was defined longitudinally as a weight for age (WFA) z-score decline ≥ 1 SD from birth, while UN was defined cross-sectionally as a WFA or length for age z-score < -2 SD at discharge. Logistic regression models were used to determine independent predictors for both growth phenotypes.

RESULTS

At discharge, the prevalence of GF and UN was 45.3% and 33.1%, respectively. In infants born without growth restriction (GR), UN was almost entirely driven by GF (89.7%). In contrast, 85.5% of infants born with GR remained undernourished at discharge. Multivariate analysis identified bronchopulmonary dysplasia and higher maximal postnatal weight loss as major independent risk factors for GF, while female sex and human milk feeding at discharge were associated with a lower risk of GF. For infants born with adequate weight, maternal hypertension, extremely low birth weight, and the co-occurrence of GF were the strongest predictors of UN.

CONCLUSIONS

Nearly half of very preterm infants experience significant growth impairment before discharge. By assessing the dynamic process of GF and the static endpoint of UN, we identified distinct clinical trajectories. Standardized ESPGHAN criteria allow for the identification of high-risk "phenotypes"-particularly those with GR at birth or severe neonatal morbidity-enabling more targeted and intensive nutritional management during the critical developmental window.