Arterial red cell indices in preterm and term infants at birth

Baseline arterial red cell indices were determined at birth in 105 infants of various gestational ages. These arterial samples were obtained through an umbilical artery catheter or radial artery puncture from a selected group of patients who were evaluated for respiratory distress or possible infection. The red cell distribution width, a quantitative measure of heterogeneity of red cells in the peripheral blood, was consistently elevated, revealing a physiologic state of anisocytosis in the newborn. This new information has provided a useful baseline reference for normal red cell indices from arterial blood in neonates in the first 24 hours of life.