Glycosylated hemoglobin and protein levels in normal and diabetic pregnancies: relation to birth weight.

Glycosylated hemoglobin and protein were measured in maternal and cord blood of 24 normal, 19 class A, and ten insulin-treated diabetics using an affinity chromatographic technique. Maternal (intrapartum) glycohemoglobin and glycoprotein levels in the diabetics were not significantly different from those in normal controls, suggesting "tight" metabolic control in these patients. Compared with controls, cord blood glycohemoglobin and glycoprotein levels were significantly higher in insulin-treated, but not in class A, diabetics. The birth weight ratio correlated significantly only with maternal glycohemoglobin in insulin-treated diabetics. The results suggest that: even in well-controlled insulin-treated diabetics, the fetuses are hyperglycemic; maternal glycohemoglobin correlates with birth weight in insulin-treated diabetics; maternal glycoprotein determinations cannot be used to predict birth weight; hyperglycemia cannot be the sole determinant of fetal overgrowth in diabetic pregnancies; factors influencing fetal overgrowth in class A and insulin-treated diabetics may be different.