Increased serum gastrin concentrations and gastric acid hyposecretion in the immediate newborn period.

Thirty-two infants and their mothers were studied to determine the source of elevated serum gastrin concentrations in umbilical blood and to learn whether neonates hypersecreted acid in response to hypergastrinemia. Gastrin concentrations in the umbilical artery and vein were similar. Both were significantly higher than maternal gastrin concentrations. No significant amount of gastrin could be measured in placental extracts. These results suggest that the increased neonatal gastrin concentrations were fetal in origin. Continuous basal acid secretory studies done for 4 hr in 32 infants and for 8 hr in 9 infants demonstrated hyposecretion of gastric acid for the first 5 hr of life. Acid secretion from hour 6 to 8 was similar to that in older children. Increased gastrin levels were still present at hour 8 and were associated with normal gastric acid secretion.