Serum bilirubin levels in the newborn infant

Abstract

Summary 1.Cord bilirubin levels of full-term“compatible”, full-term “incompatible”, and premature infants are essentially the same. The average cord bilirubin level of infants with erythroblastosis is more than double that of infants without erythroblastosis and a level above 5 mg. per cent is strongly suggestive of this disease. 2.Normal infants usually show a rise of bilirubin during the first day of life, but infants with erythroblastosis show a marked elevation during this period. 3.Normal full-term infants reachtheir peak elevation of bilirubin at about two days of life, whereas the peak bilirubin of premature infants is attained on the fourth day of life, on the average. The peak elevation of bilirubin of premature infants not only occurs later than that of full-term infants, but reaches higher levels, confirming the clinical impression that physiological jaundice is more severe and more prolonged in the premature infant than in the full-term infant. 4.In this series, infants with erythroblastosis,treated by exchange transfusion, have their bilirubin peak during the second day of life, on the average. Exchange transfusion greatly modifies the bilirubinemia in these infants. A level of serum bilirubin above 10 mg. per cent during the first twenty-four hours of life, or the appearance of skin icterus during this period, must be considered due to erythroblastosis until proved otherwise. 5.Determinations of the level ofserum bilirubin during the first two days of life are of great diagnostic value with respect to erythroblastosis, particularly in cases caused by ABO incompatibility. They are of even greater value as a therapeutic guide in the use of replacement transfusion. Summary 1.Cord bilirubin levels of full-term“compatible”, full-term “incompatible”, and premature infants are essentially the same. The average cord bilirubin level of infants with erythroblastosis is more than double that of infants without erythroblastosis and a level above 5 mg. per cent is strongly suggestive of this disease. 2.Normal infants usually show a rise of bilirubin during the first day of life, but infants with erythroblastosis show a marked elevation during this period. 3.Normal full-term infants reachtheir peak elevation of bilirubin at about two days of life, whereas the peak bilirubin of premature infants is attained on the fourth day of life, on the average. The peak elevation of bilirubin of premature infants not only occurs later than that of full-term infants, but reaches higher levels, confirming the clinical impression that physiological jaundice is more severe and more prolonged in the premature infant than in the full-term infant. 4.In this series, infants with erythroblastosis,treated by exchange transfusion, have their bilirubin peak during the second day of life, on the average. Exchange transfusion greatly modifies the bilirubinemia in these infants. A level of serum bilirubin above 10 mg. per cent during the first twenty-four hours of life, or the appearance of skin icterus during this period, must be considered due to erythroblastosis until proved otherwise. 5.Determinations of the level ofserum bilirubin during the first two days of life are of great diagnostic value with respect to erythroblastosis, particularly in cases caused by ABO incompatibility. They are of even greater value as a therapeutic guide in the use of replacement transfusion.