Determination of levels of carcinoembryonic antigen and nonspecific cross-reacting antigen in the sera of neonatal infants: brief communication.

Seventy-eight sera from neonatal infants, born at full term or prematurely, were studied for their carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) concentrations, which were compared to the normal adult concentrations. The levels of CEA in the sera were significantly higher in newborns than in adults: 9.05 ng CEA/ml in newborns as compared to 2.5 ng CEA/ml in adults (P=0.001). The levels of NCA in the sera were also higher in newborns: 164 ng NCA/ml in newborns as compared to 130 ng NCA/ml in adults. This difference in NCA levels was not significant, although 80% of the newborns had increased values (greater than 130 ng/ml). Whether the infant was born at full term or prematurely and whether the infant was a boy or girl had no statistically significant influence on the concentration of the CEA and the NCA in the infant.