Metabolic adaptations during the neonatal period in infants of diabetic mothers.

Infants of diabetic mothers (IDM's) are prone to develop severe but usually asymptomatic hypoglycaemia during the first postnatal hours. High maternal plasma glucose concentrations at the time of delivery increase this risk, especially if the mode of delivery is cesarean section. Newborn IDM's are hyperinsulinaemic and the neonatal hypoglycaemia seems to result from this together with a retarded increase in plasma glucagon levels. Despite very high plasma insulin concentrations, lipolysis, as indicated by a rise in plasma glycerol concentrations, appears to be normal in IDM's. The IDM's are able to respond to both physiologic and metabolic stress with an increased catecholamine secretion during the first hours of life, and the catecholamines seem to counteract the inhibitory effect of insulin on lipolysis and, at least partly, to oppose the blood glucose lowering effect of insulin.