Neutropenia and intraventricular hemorrhage among very low birth weight (less than 1500 grams) premature infants.

To assess the previously reported association of intraventricular hemorrhage (IVH) with neutropenia, we prospectively followed during a 38-month study period infants with birth weight less than or equal to 1500 gm who survived greater than 72 hours and underwent serial cranial sonography and neutrophil counts for the first 14 days of life. Neutrophil counts were interpreted according to a widely employed reference range. Infants with conditions other than IVH reported to be associated with neutropenia (sepsis, maternal hypertension, 5-minute Apgar score less than or equal to 5) were excluded. Final study groups included 38 infants with IVH and 114 without IVH. No significant differences were found for birth weight, gestational age, respiratory distress syndrome, mechanical ventilation, prolonged rupture of membranes, patent ductus arteriosus, route of delivery, pneumothorax, or sex. The occurrence of neutropenia before 14 days of age was not significantly different between the groups (50% with IVH, 56% without IVH), nor were differences found at individual postnatal ages. Comparison of immature neutrophil count and immature/total neutrophil ratio also revealed no differences. The high incidence of neutropenia in our non-IVH group raises questions about application of these widely accepted reference ranges to very low birth weight infants.