The Relationship Between Early Weight Z-Score Changes and Nutritional Differences in Very Low Birth Weight Infants During Hospital Stay

Advances in neonatal care have resulted in improved survival for very low birth weight infants (VLBWIs). However, the main factors that lead to early weight Z-score [standard deviation score (SDS)] changes during hospital stay in VLBWIs still need to be studied more.
In this study we aimed to investigate the differences in specific factors that relate to VLBWIs’ early weight Z-score changes as the scientific basis for clinical practice of VLBWIs during the entire hospital stay.
We retrospectively reviewed baseline characteristics, nutrition management, clinical outcomes, and complications between non-catch-down (NCD) (Δ weight SDS ≥ -0.67) and catch-down (CD) groups (Δ weight SDS A total of 227 infants (NCD group = 117, CD group = 110) met the inclusion criteria. No significant differences were found in baseline characteristics between the two groups. The NCD group received higher parenteral lipids (g/kg/d) from day 5 to day 7 and higher enteral feeding volume (mL/kg/d) from day 5 to week 5. The NCD group had higher protein:energy ratios at day 2 to day 4 and day 7 and higher total energy (kcal/kg/d) during the first six weeks. The NCD group had lower incidence of bronchopulmonary dysplasia (BPD) and parenteral nutrition-associated cholestasis (PNAC).
This study showed that adequate parenteral lipid and energy at the first week of life and earlier enhanced enteral feeding volume might significantly improve the VLBWIs’ weight Z-scores during hospital stay. The VLBWIs with catch-down growth might be more prone to developing BPD and PNAC.