Hémogramme en pédiatrie : variations physiologiques

Blood cell counts and indices are profoundly modified during the first years of life and reflect the important changes during fetal development. We report and point out, in this review, the differences and the major factors that impact the normal hematologic values in healthy term and preterm neonates and infants. Important preanalytic factors, such as limited volume blood samples or effect of the drawing out puncture site will be exposed. We will focus on the characteristics of fetal hematopoiesis and exposed the variations of normal values for blood parameters (hemoglobin concentration, hematocrit, erythrocyte indices, blood neutrophil concentration…) during childhood. The main cytological peculiarities of the blood cells in neonates will also be reviewed. Indeed, knowledge of the qualitative physiological changes in the newborn is essential for an accurate interpretation of morphological abnormalities.