Weight growth velocity and neurodevelopmental outcomes in extremely low birth weight infants

Introduction This study aimed to assess whether weight growth velocity (WGV) predicts neurodevelopmental outcomes in extremely low birth weight infants (ELBWIs). Methods Subjects were infants who weighed 501-1000 g at birth and were included in the cohort of the Neonatal Research Network of Japan (2003-2007). Patel's exponential model (EM) method was used to calculate WGV between birth and discharge. Assessment of predictions of death or neurodevelopmental impairment (NDI) was performed at 3 years of age based on the WGV score, which was categorized by per one increase in WGV. Multivariate logistic regression analysis was used to calculate adjusted odds ratios and their 95% confidence intervals (95%CI). Results In the 2961 ELBWIs assessed, the median WGV was 10.5 g/kg/day (interquartile, 9.4- 11.9). With the categorical approach, the adjusted odds ratios for death or NDI with WGV scores of 6 and 7 were 2.41 (95%CI, 1.60-3.62) and 1.81 (95%CI, 1.18-2.75), respectively, relative to the reference WGV score of 10. WGV scores ≥8 did not predict death or NDI. Conclusions WGV scores <8 were significant predictors suggesting that values of WGV during hospitalization in a NICU are associated with neurodevelopmental outcomes. Further investigations is necessary to determine whether additional nutritional support may improve low WGV in ELBWIs.