Neonatal Absolute Nucleated Red Blood Cell Counts do not Predict the Development of Cystic Periventricular Leukomalacia

Background: Infants with severe intraventricular-periventricular hemorrhage (IVH) have higher absolute nucleated red blood cell counts (aNRBC) at birth (a marker of intrauterine hypoxia) than controls. Periventricular leukomalacia (PVL) is known to be associated with prenatal and postnatal events. Whether PVL is also linked to intrauterine hypoxia is unknown. Objectives: To test the hypothesis that infants with PVL have higher aNRBC counts at birth than controls. Methods: We studied 14 very low birth weight infants with PVL and compared them with 14 pair-matched controls without PVL. Head ultrasound scans were performed in all infants on days 3-5 and 21-25 of life. Paired tests, Fisher exact tests and stepwise logistic regression were performed for analysis. Results: The groups were similar for gestational age (GA), birth weight (BW), prolonged rupture of membranes (PROM), Apgar scores, IVH, and aNRBC counts. PVL correlated significantly with low partial pressure of CO2 (PCO2) and IVH (P < 0.01). In logistic regression, when GA, gender, PROM, antenatal steroid therapy, 1 (or 5) minute Apgar scores, IVH grade, nosocomial sepsis, patent ductus arteriosus, necrotizing enterocolitis (NEC), need for pressors, aNRBC counts and lowest PCO2 were used as independent variables, PCO2 (P = 0.002), IVH grade (P = 0.001), GA (P = 0.038), NEC (P= 0.061) and use of dopamine (P = 0.010) remained in the analysis (total R-2 = 68.2%). Conclusions: In contrast to severe IVH, aNRBC counts do not predict the development of PVL. IMAJ 2012; 14: 420-423