Influence of maternal metabolic control and insulin antibodies on neonatal complications and B cell function in infants of diabetic mothers.

Circulating insulin antibodies at birth and the degree of maternal metabolic control were measured in 68 infants of insulin-treated diabetic mothers. Their correlation with neonatal B cell function and with the clinical features of the infants was evaluated in order to better understand their influence on fetal outcome. Maternal metabolic control was assessed on the basis of blood glucose levels, glycosuria and the occurrence of hypoglycemia and/or ketonuria. All infants were clinically evaluated for gestational age, macrosomia, hypoglycemia, hyperbilirubinemia, hypocalcemia, and respiratory distress syndrome. Cord blood plasma glucose, C peptide, and IgG insulin antibodies were also measured. It was shown that poor maternal metabolic control was associated with a higher prevalence of fetal morbidity as well as with signs of B cell hyperfunction. Also the presence of circulating insulin antibodies correlated well with higher C peptide levels and with several neonatal complications. B cell hyperfunction, indicated by high C peptide levels in the infants of diabetic mothers, may possibly play a causal role in the pathogenesis of fetal morbidity. In conclusion, a good fetal outcome in insulin-treated diabetic pregnancies was associated with and may have depended upon: (1) good maternal metabolic control, and (2) absence or low levels of circulating insulin antibodies.