A newborn infant represents the culmination of developmental events from conception
through organogenesis. Red cells are critically important for survival and growth of the
embryo. During development, erythropoiesis occurs in two distinct forms. The first
'primitive'form consists of nucleated erythroblasts that differentiate within the blood vessels of
the extraembryonic yolk sac. The second 'definitive'form consists of anucleate erythrocytes
that differentiate within the liver and third trimester bone marrow of the fetus. While adult …