Hematology and immunology: Overview

Abstract

“Normal ranges” for hematologic values of neonates are generally not available. This is because blood is not drawn on healthy normal neonates to establish such ranges, as is done with the consent of healthy adult volunteers. Instead, neonatal hematology generally utilizes “reference ranges”. These ranges consist of 5th to 95th percentile values compiled from laboratory tests that were performed on neonates thought to have minimal pathology relevant to the laboratory test, or with pathology unlikely to significantly affect the test results. The premise on which the reference range concept is based is that these values approximate normal ranges, although they were admittedly obtained for a clinical reason and not from healthy volunteers.