Relative rates of fetal hemoglobin and adult hemoglobin synthesis in cord blood of infants of insulin-dependent diabetic mothers.

Erythrocytosis, extramedullary erythropoiesis, and increased levels of plasma erythropoietin have been observed in newborn infants of diabetic mothers. Because there is evidence that there is a relationship between increased fetal hemoglobin production and acute erythropoietic expansion, it was considered important to study the proportion of fetal hemoglobin and adult hemoglobin synthesis in newborn infants of insulin-dependent diabetic mothers. Samples from nine newborn infants of diabetic mothers as well as nine control infants, ranging from 36 to 38 weeks of gestation, were incubated in an amino acid mixture containing [14C]leucine. The adult hemoglobin and fetal hemoglobin were then separated by column chromatography on DEAE [O-(diethylaminoethyl)] Sephadex. To confirm that the fetal hemoglobin obtained after Sephadex chromatography was not contaminated with other hemoglobins, several of the DEAE separations from each group were reconstituted and subjected to polypeptide chain elution using carboxyl-methyl cellulose chromatography. The data demonstrated that the newborn infants of diabetic mothers are synthesizing significantly more fetal hemoglobin than is expected for their period of development (82.2 +/- 3.6 v 72.8 +/- 4.2; P less than .005). It is suggested that the in utero environment of the fetus of the diabetic mother causes an increase in fetal hemoglobin synthesis.