Glucose and oxygen metabolism in normally oxygenated and spontaneously hypoxemic fetal lambs.

Whole blood glucose and oxygen concentration were measured in chronically catheterized fetal lambs, some of whom had implanted common umbilical artery flow transducers. Ten of the fetuses were well oxygenated (femoral arterial PaO2 less than 18 torr) and 13 fetuses had evidence of chronic hypoxemia (femoral arterial PaO2 less than 18 torr). The mean glucose uptake (54.0 +/- 7.6 S.E.M. mM. per kilogram per day), umbilical blood flow (230 +/- 13 S.E.M. ml. per kilogram per minute), and glucose/oxygen ratio (0.503) were the same in both fetal groups. The oxygenated fetuses had higher glucose levels at ang given maternal glucose concentration than the hypoxemic animals (p less than 0.001y and showed a correlation between glucose again across the placental circulation and the transplacental driving force for glucose (p less than 0.002). The hypoxemic fetuses, who had a higher per kilogram oxygen consumption than the oxygenated fetuses (p less than 0.05), showed no correlation between the amount of glucose taken up and the transplacental glucose concentration gradient.