Blood Formation in Infancy: Part I.--The Normal Bone Marrow

Abstract

A complete account of the changes in the blood picture in infancy requires a knowledge of the rates of formation and destruction of blood. Since the latter is not easily measured, our approach has been to use the activity of bone marrow as a measure of blood formation, and then to deduce whether changes in blood formation alone are sufficient to account for observed changes in the blood picture. Part I of the study, therefore, consists of an account of the marrow picture during the first three months of life. Part II concerns erythropoiesis, and the marrow findings are then considered together with the blood picture. Matenal and MethodsThe data to be discussed are derived from a total of 102 specimens of marrow from 25 infants aged from a few minutes to three months. A sample of venous blood was taken at the same time as the marrow.The infants were born in the Cambridge Maternity Hospital; the majority were chosen because their mothers had already borne a normal infant at the hospital and had volunteered to take part in the investigation; three subjects were mongols, but as their weight gains proved normal during the period under review, they were included in the series. Labour and delivery were normal, miniaial nitrous oxide and air anaesthesia being given to the mothers. Birth weights exceeded 6 lb. The cord was clamped as soon as conveniently possible, but usually some 10 to 15 seconds elapsed before this was done. Infants developing more than trivial infections were excluded. Sixteen of the 25 infants were completely breast fed. Weight gains were satisfactory and the infants generally were healthy and well cared for.

Origins of the discipline ‘neonatal haematology’, 1925–75

“…In subsequent studies, Dr Halvorsen observed lower plasma erythropoietin concentrations in the cord blood of preterm infants at delivery than in term neonates at delivery (Halvorsen & Finne, 1968). These observations supported the concept of Gairdner et al (1952a, b) that the postnatal fall in erythropoiesis (the ‘physiologic anaemia’ of neonates) is as a result of an increase in oxygen delivery to tissues following birth and is mediated by a fall in circulating erythropoietin concentration. The observations gave rise to the postulate that the ‘anaemia of prematurity’ was an exaggeration of this physiological anaemia and involved a limitation of preterm infants to appropriately increase erythropoietin production.…”

“…Normal values for haemoglobin, haematocrit, erythrocyte indices and leucocyte concentrations were refined by DeMarsh et al (1942, 1948), and in a series of publications in the early 1950s in Archives of Diseases of Children by Gairdner et al (1952a, b). These were followed by observations on human fetal haematopoiesis by Thomas and Yoffey in the British Journal of Haematology (Thomas & Yoffey, 1962, 1964), and by the work on blood volume during the 1960s (Usher et al , 1963, Usher & Lind, 1965; Yao et al , 1967, 1968).…”

“…In the early 1950s, Douglas Gairdner, John Marks and Janet D. Roscoe, of the Department of Pathology of Cambridge Maternity Hospital, published pioneering studies in blood formation in infancy (Gairdner et al , 1952a, b). Studying 105 blood samples and 102 bone marrow samples, they concluded that ‘erythropoiesis ceases when the oxygen saturation just after birth increases from about 65% in the umbilical vein to > 95% just after birth’.…”

Alterations of Red Blood Cells’ Polyamines during Pregnancy and Neonatal Period

“…6, table IV) seem to be reflected by two facts, namely, polyamine appears to be affected by the ac celerated fetal bone marrow erythropoiesis [4] and rapid fetal growth. This phenomenon resembles the finding that polyamine concen trations are elevated in some cancer patients.…”

The Limits of Physiological Anemia in the African Neonate

“…It has been demonstrated that a normal term in fant shows erythroid hypoplasia [2,4,13] during the period of physiologic anemia. Garby et al [3] also demonstrated a remarkable decline in red cell produc tion after the first few days of life which persists until about 8 weeks of life.…”