Physiology of serum gastrin production in neonates and infants.

Conflicting data exist regarding the physiology of serum gastrin production in neonates and infants, and the response of the neonatal gastric antrum to feeding. Normal neonates and infants underwent serial determination of fasting and postprandial serum gastrin levels from birth to 4 months of age. The mean fasting serum gastrin levels in newborns and infants up to 4 months remained considerably higher than the mean maternal levels, the elevations being statistically significant until 2 months of age. In addition, in the first 2 months of life, there was no evidence of postprandial stimulation of serum gastrin levels 30 minutes following normal feeds consisting of breast milk or commercial formula. At 3 and 4 months of age, the response appears to revert to an adult pattern with statistically significant postprandial elevations following normal feeds (p = 0.003 and p = 0.02, respectively). This study confirms the presence of neonatal hypergastrinemia and reveals a persistence of elevated serum gastrin levels through early infancy. A maturation of the antral gastrin release response with postprandial elevations of serum gastrin levels occurs at approximately 3 months of age.