Persistence and Utilization of Maternal Iron For Blood Formation During Infancy

Abstract

During the course of investigations of maternal red cell volume, employing transfusions with radioactive iron, an opportunity was afforded to measure the persistence and utilization of iron transferred across the placenta to the infant. A wealth of fundamental data was obtained concerning the importance of iron obtained from the mother in hematopoiesis during infancy. As the donors' cells containing radioactive iron which were transfused during pregnancy were broken down, radioactive iron was released into the general supply of the mother and fetus. At birth the blood of each infant contained a measurable ratio of radioactive iron to packed red cells. The ratio of radioactive iron to hemoglobin and to hemoglobin iron could then be calculated. Further calculations gave information concerning the amounts of hemoglobin iron of transplacental and dietary origin. The results indicated that there was little or no utilization of dietary iron for hemoglobin formation by the infants until 3 to 4 months after birth. Incorporation of the radioactive iron obtained transplacentally into hemoglobin during the growth of the infant indicated that normal infants utilize iron obtained during fetal life throughout infancy. Data from infants followed for a long period suggest that after 3 to 4 months dietary iron continues to be added to transplacental iron for the production of hemoglobin and gradually begins to replace transplacental iron in hemoglobin formation during the third year.