The pattern of fetal haemoglobin disappearance after birth.
Haemoglobin F (Hb F) levels were determined in 209 full-term newborn babies or infants of different ages ranging from birth to 11 months. A follow-up study of the disappearance of Hb F after birth was carried out on 25 premature babies; they were followed periodically from birth until 8 months. The results obtained in both samples show that Hb F levels remain constant after birth for periods varying from about 15 d in at term babies to about 40 d in premature babies; a linear decrease follows in both cases. The initial plateau is a finding contrary to what has been reported. A possible model for the phenomenon is discussed in terms of haemoglobin genes and ontogenetic differentiation.
D000367:Age Factors; D005260:Female; D005319:Fetal Hemoglobin / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013997:Time Factors
D006454:Hemoglobins; D005319:Fetal Hemoglobin