Early anemia and neonatal morbidity in extremely low birth-weight preterm infants

Background: Extremely low birth-weight (ELBW) preterm infants remain at high risk for mortality and major morbidities, and nearly all need packed red blood cell transfusions within their first weeks of life. The overall objective of this study was to assess the association between anemia at admission to neonatal intensive care unit (NICU) with the neonatal morbidity and mortality in ELBW infants. Methods: This retrospective study was conducted on 106 patients with ELBW admitted at our level III NICU from January 2006 to December 2015. The subjects were divided into two groups: (1) patients with anemia at admission and (2) patients without anemia. Their characteristics and outcomes were compared. Statistical analysis was performed using the Statistical Package for the Social Sciences software, version 24.0 (IBM New York, USA), and a value of p < 0.05 was considered statistically significant. Results: Of the 106 ELBW, 34 (32%) presented with anemia at admission and 72 (68%) without anemia. Anemia-naive presented mean hemoglobin at the admission of 12.8 +/- 1.5 g/dl and nonanemic 16.8 +/- 2.1 g/dl, p < .001). The anemic group presented a lower gestational age (26 +/- 2 vs. 27 +/- 2 SD weeks, p = .025), greater need for inotropic support (52.9 vs. 31.9%, p = .041), longer period of invasive mechanical ventilation (9 vs. 2 days, p = .012), higher FiO(2) need (0.8 vs. 0.4, p < .001), more frequent hemodynamically significant patent ductus arteriosus (HS-PDA) (64.7 vs. 41.7%, p = .006) and severe intra-periventricular hemorrhage (IPVH) (41.2 vs. 16.7%, p = 0.005). The multivariate analysis confirmed an association between anemia at admission and HS-PDA (OR = 3.2; 95% CI: 1.1-9.5, p = 0.044) and severe IPVH (OR = 3.3; 95% CI: 1.0-9.9, p = .038). In anemic infants, ionotropic support and IPVH >2 were considered independent factors for mortality. Conclusion: In this ELBW series, the presence of anemia at admission to the NICU was associated with HS-PDA and severe IPVH. Preventive strategies for early anemia must be encouraged.