Association between reticulocyte hemoglobin content (RetHe) and neurodevelopmental outcomes in preterm infants

OBJECTIVE: Investigate the impact of reticulocyte hemoglobin content (RetHe) on neurodevelopment in preterm infants. STUDY DESIGN: weeks gestational age (GA) with neurodevelopmental testing post-discharge. Associations between neurodevelopment and average RetHe, lowest RetHe, and exposure time to low RetHe ( < 29 pg) were described and stratified by GA. RetHe over time and test Z-scores were assessed using multivariable linear regression. RESULTS: 52% of 381 infants (N = 199) had at least 1 low RetHe. Infants with abnormal development had lower average and minimum RetHe, and longer exposure to low RetHe (all p ≤ 0.003). RetHe was highest in infants born 32-33 weeks GA. Higher RetHe during postnatal weeks 1-5 was associated with higher Test of Infant Motor Performance Z-scores (p = 0.0048), with diminishing effect over time, but decreasing 12-month Bayley cognitive Z-scores (p = 0.0064). CONCLUSION: RetHe is associated with neurodevelopment and potentially has differential effects based on GA and postnatal age.