Red cell enzymes in cord blood and plasma bilirubin levels in the first week of life

Abstract

Cord blood of 300 randomly selected healthy full-term newborn babies (98 Chinese, 102 Malays and 100 Indians) was examined for maternal—foetal blood group incompatibility, haemoglobin types, glutathione level and activities of glucose-6-phosphate dehydrogenase, glutathione reductase, glutathione peroxidase, pyruvate kinase and methaemoglobin reductase, and each newborn's total plasma bilirubin level was estimated daily for one week. 5.6% of the babies developed severe hyperbilirubinaemia of 15 mg/100 ml or higher, three requiring exchange blood transfusion. Babies with maternal—foetal blood group incompatibility and glucose-6-phosphate dehydrogenase deficiency had significantly higher mean bilirubin curves than “normal” babies. Among newborns without known abnormalities Chinese had the highest mean bilirubin curve, Indians the lowest. In all three races, maximum bilirubin level was reached on the fourth day. Neonates with low glutathione reductase activity had a significantly higher mean bilirubin curve. No such pattern was seen for glutathione, glutathione peroxidase, pyruvate kinase or methaemoglobin reductase.