66 Association of Low Hemoglobin at Birth and Neurodevelopmental Outcomes in Preterm Neonates < 29 Weeks’ Gestation: A Retrospective Cohort Study

Background Low hemoglobin (Hb) at birth is not an uncommon presentation for infants born preterm. The association of early anemia and neurodevelopmental outcomes in extremely preterm infants is not well studied. Objectives The objective of this study was to assess neurodevelopmental outcomes at 18-24 months corrected age (CA) of preterm infants with Hb <120 gm/l compared to those with Hb ≥120 gm/l at birth. Design/Methods In this retrospective cohort study, infants of <29 weeks’ gestational age (GA) with an Hb result at birth and admitted to one of two Canadian tertiary care NICUs between January 2009 and June 2018, were included. Baseline sociodemographic, antenatal, and neonatal data were compared between groups. The primary outcome was neurodevelopmental impairment (NDI), defined as the presence of one or more of: cerebral palsy; motor, cognitive, or language impairments on standardized testing; or visual or hearing impairment, at 18-24 months. Secondary outcomes included significant NDI (sNDI), death, severe retinopathy of prematurity (ROP) (≥ stage 3), grade III intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, bronchopulmonary dysplasia (BPD), and composite outcomes of death or NDI. Multivariable logistic regression adjusting for GA, small for GA (SGA), sex, birth centre, and antenatal steroids, was used to determine the association between early anemia and outcomes. Results Of the 2351 eligible neonates, 351 (14.9%) had Hb levels <120 gm/L at birth. Baseline characteristics for groups are summarized in Table 1. Of the infants who survived, 1534 (72.5%) had developmental follow-up at 18 to 24 months CA. Low Hb was associated with significantly higher odds of NDI among survivors in univariate analyses but not in multivariable logistic regression (Table 2). The composite outcome of death or NDI was significantly higher in the low Hb group, primarily driven by the higher incidence of mortality. Neonatal death, IVH, ROP, and BPD were significantly higher in the low Hb group. Conclusion In preterm infants of <29 weeks’ GA, low Hb at birth was not associated with significant NDI outcomes at 18-24 months. However, low Hb was associated with higher odds of death, severe IVH, severe ROP, and BPD.