Persistence and Utilization of Maternal Iron for Blood Formation During Infancy 12

The concentration of hemoglobin in the blood of normal infants falls progressively during the first 4 to 6 weeks following birth. The decline results primarily from reduced hematopoiesis, though iron is present for the manufacture of hemoglobin and replacement of erythrocytes. The slow rise in hemoglobin concentration which occurs during the remainder of infancy may be affected by several factors, including the rapidity of body growth, the amount and absorption of dietary iron, and the amount and conservation of iron which was obtained transplacentally (1). An opportunity to measure the persistence and utilization of trans- placental iron during infancy arose as a by-product of investigations of maternal red cell volume and hematocrit recently published from this hospital (2, 3).