Serum bilirubin levels in the newborn infant and their relation to clinical icterus and liver function studies

Abstract

Summary Hemoglobin, hematocrit, and blood liver function studies were performed on twenty-five normal newborn infants during the first two days of life and repeated forty-eight to seventy-two hours later. Attempts were made to correlate total serum bilirubin with liver function studies, changes in the hemoglobin and hematocrit level and the degree of clinical icterus. No correlation could be established between the total serum bilirubin levels and the blood liver function studies. Even after a period of forty-eight to seventy-two hours had elapsed in cases where the blood bilirubin level was elevated, there were no signs of hepatic dysfunction as evidenced by abnormal liver function studies. Not all cases showed a significant drop in hemoglobin and hematocrit associated with a rise in serum bilirubin. Conversely, some cases showed an appreciable rise in bilirubin with little or no change in hemoglobin or hematocrit. In not all instances could the total serum bilirubin be directly correlated with the extent of clinical jaundice. In some cases jaundice was noted where the bilirubin level was only moderately elevated, whereas in other cases there was no jaundice with appreciably elevated serum bilirubin. When total serum cholesterol studies were performed on infants during the first or second day of life, the results tended to be significantly lower than the level obtained on the same infant on the third to fifth day of life.