Post-Discharge Growth Trajectories in Very Low Birth Weight Infants: Predictors of Catch-Up Growth Failure

Abstract

Introduction: Very low birth weight (VLBW, <1500g) infants remain at risk for poor post-discharge growth, which predicts neurodevelopmental outcomes. Identifying modifiable predictors of catch-up growth failure (weight-for-age z-score decline >1) would inform follow-up strategies.

Methods: We conducted a systematic review of cohort studies (≥6 months post-discharge follow-up) reporting growth trajectories in VLBW infants. Databases: PubMed, Scopus, LILACS. Primary outcome: proportion with poor catch-up growth at 12 months corrected age. Predictors: extrauterine growth restriction (EUGR) at discharge, exclusive formula feeding, maternal education, neonatal morbidities. Meta-regression used.

Results: Sixteen cohorts (n=5,673 VLBW infants) were included. At 12 months, 37% (95% CI 31–44%) had failed catch-up growth (z-score decline or persistent <–2). Strongest predictor was severe EUGR at discharge (weight z-score <–2; OR 4.2, 95% CI 2.9–6.1). Exclusive formula feeding (vs. breast milk with fortifier) increased risk (OR 1.8, 95% CI 1.3–2.5). Maternal education <12 years conferred OR 2.1 (1.4–3.1). Neonatal BPD and NEC were not independently predictive after adjusting for EUGR.

Discussion: Discharge anthropometry is the dominant predictor of subsequent growth. Breast milk-based fortifiers appear protective, possibly due to immunomodulatory effects reducing subclinical inflammation. Limitation: heterogeneous definitions of catch-up across studies.

Conclusions: VLBW infants with discharge weight z-score <–2 are at high risk for sustained growth failure. Targeted post-discharge nutritional intervention, including continued fortified feeds and nutritionist follow-up, should be prioritized for this group.