J Korean Pediatr Soc.  1980 Dec;23(12):991-998.

Fetal Erythrocyte Content of Normal Newborn Infants

• Kim KB

Abstract

The fetal erythrocyte (HbF-cell) content in the blood of the newborn infants was measuted in 945 newbo- rns whose gestational days were certain, among 2373 normal deliveries during the year 1978 in this hospital. Within 48 hours of birth a few drops of blood were obtained by heel puncture of the babies and thin blood films were prepared, and the fetal erythrocyte content was counted under microscope, utilizing the ac- id-elution technique of Kleihauer and Betke. Transitional forms containing both adult and fetal hemoglobin were included in fetal cells. The results obtained were as follows : 1) Mean HbF-cell count of 945 cases was 90.7% with S. D. of 5.45%. 2) No sex difference was found in the HbF-cell content. 3) The HbF-cell content varied inversely with the gestational age, i. E., infants with shorter gestation tended to have higher HbF-cell content, and it decreased as the gestational period increased. 4) From the regression equation, Y=126.3-0.87X(Y=HbF-cell content ; X=gestational week), it was suggested that the HbA-cells (erythrocytes containing only adult hemoglobin) begins to appear in the circulation from the 30th gestational week, and that the HbF-cell content decreases 0.87% a week thereafter. 5) In general, the HbF-cell content varied inversely also with the body weight at birth. However, no significant difference of HbF-cell content was found among weight groups within the same gestational group, indicating that the body weight was not the primary determinant of the HbF-cell content. 6) No difference in HbF-cell content was found in different blood groups.

MeSH Terms

Adult
Blood Group Antigens
Body Weight
Erythrocytes*
Fetal Hemoglobin
Gestational Age
Heel
Humans
Infant
Infant, Newborn*
Parturition
Pregnancy
Punctures
Sex Characteristics
Blood Group Antigens
Fetal Hemoglobin