Carbohydrate metabolism in pregnancy. Part II. Relation between maternal glucose tolerance and glucose metabolism in the newborn.

The objective of clinical management of the pregnant diabetic woman is to prevent the serious adverse effects of an abnormal glucose environment on the fetus. Neonatal glucose assimilation and insulin release over the first two hours of life were correlated with various indices of maternal carbohydrate metabolism in the third trimester. Of the 31 mothers studied 21 were defined as normal and 10 as having chemical diabetes. Neontal glucose assimilation during the first two hours of life correlated strongly with functions of both maternal glucose tolerance and mean diurnal glucose level, the strongest correlation being with the area under the three-hour oral glucose tolerance curve (P less than 0.001), Two-hour neonatal plasma glucose values of under 1.7 mmol/1 (30 mg/100 ml) were found only in the newborn of women whose glucose tolerance area measured over 41.6 area units (750 traditional units); thus, even in the borderline diabetic range glucose tolerance testing during the last trimester of pregnancy may be valuable in predicting likelihood of neonatal hypoglycaemia. The findings also shed light on the possible sensitizing role of mild maternal hyperglycaemia on fetal insulin production and secretion.