Diabetes in pregnancy: Effect on glycation and acetylation of the different chains of fetal and maternal hemoglobin

BackgroundMeasurement of glycated fetal hemoglobin to assess maternal glycemic control is unreliable. Electrospray ionization–mass spectrometry (ESI-MS) has been suggested as a definitive procedure.ObjectiveThis study aimed to evaluate glycation and acetylation by ESI-MS of the separate chains of neonatal fetal hemoglobin in comparison with glycation of maternal hemoglobin, to assess the impact of maternal diabetes.MethodsTwenty-nine non-diabetic (31 neonates) and 15 diabetic women (15 neonates) were recruited. Whole blood was collected at delivery from the mothers and cord blood from their respective neonate. The blood samples were diluted in acetonitrile:water (50:50) and treated with a cation exchange resin to remove sodium and potassium adducts on the hemoglobin. The α- and β-chain glycated maternal hemoglobin and α- and γ-chain glycated and acetylated hemoglobin of the neonate were measured by ESI-MS. HbA1c was measured on the Menarini 8160.ResultsMean α- and γ-chain and overall glycated hemoglobin and acetylated fetal hemoglobin were 1.23 ± 0.41%, 1.62 ± 0.47%, 1.24 ± 0.37%, and 8.56 ± 0.84% in the infant of the non-diabetic mother (INDM) and 1.39 ± 0.21%, 1.92 ± 0.61%, 1.64 ± 0.59%, and 8.44 ± 0.63% in the infant of the diabetic mother (IDM). Mean maternal α- and β-chain, overall glycated hemoglobin and HbA1c were 1.98 ± 0.38%, 4.28 ± 0.76%, 3.13 ± 0.51%, 5.39 ± 0.39% (non-diabetic) and 2.40 ± 0.83%, 4.71 ± 0.90%, 3.58 ± 0.83%, 6.15 ± 0.71% (diabetic). Overall glycated hemoglobin levels were significantly higher in the IDM (p = 0.006) compared to the INDM. Maternal glycated hemoglobin was significantly higher than neonatal glycated hemoglobin in the control (p < 0.0001) and diabetic group (p < 0.0001). A significant correlation was observed between maternal glucose concentration and overall glycated fetal hemoglobin in the IDM (p = 0.02). Glucose concentrations in the diabetic mother and the IDM were not significantly different (p = 0.5) and were significantly correlated (p < 0.0001). HbA1c was not significantly different in the two maternal groups. No significant difference was observed between AcHbF in IDM or INDM (p = 0.61).ConclusionsMeasurement of overall glycated fetal hemoglobin, incorporating α- and γ-chain glycations, seems best to assess abnormal glucose homeostasis during pregnancy. Accurate assay of this parameter is critical for stratification of risk of possible post birth developmental complications.