Association of low hemoglobin at birth and neurodevelopmental outcomes in preterm neonates ≤28 weeks' gestation: a retrospective cohort study

Objective: To compare neurodevelopmental outcomes at 18-24 months corrected age (CA) for preterm infants who had hemoglobin levels <120 g/l versus those with hemoglobin level >= 120 g/l at birth. Methods: We included infants of <= 28 weeks gestational age (GA) born between January 2009 and June 2018. The primary outcome was neurodevelopmental impairment (NDI) at 18-24 months. Multivariable logistic regression was applied to determine the association. Results: Of the 2351 eligible neonates, 351 (14.9%) had hemoglobin levels <120 g/L at birth. Of the 2113 surviving infants, 1534 (72.5%) underwent developmental follow-up at 18-24 months CA. There was no statistically significant difference in ND outcomes between the two groups. The composite outcome of death or NDI was significantly higher in the low hemoglobin group. Conclusion: In preterm infants <= 28 weeks GA, initial hemoglobin <120 g/L at birth was not associated with neurodevelopmental impairment at 18-24 months CA among survivors.