Transcutaneous bilirubin measurement in evaluating neonatal jaundice among Saudi newborns

Transcutaneous bilirubin measurements, using the Minolta transcutaneous bilirubinometer (TcB), were performed in 68 full-term, healthy Saudi infants. Infants who had exchange transfusion and those under phototherapy were excluded. One hundred and twenty measurements were obtained and compared with serum bilirubin levels measured by the American Optics (A.O.) bilirubinometer. The serum bilirubin range was 3.8-18.4 mg/dl. The results showed that the TcB index correlates well with the serum bilirubin measurement: the regression analysis was: r = 0.878, y = 10.78 + 0.909 x, P less than 0.001. However, the regression line showed that at a serum bilirubin level above 12.9 mg/dl the sensitivity of the TcB was 69% and the specificity 92%, while its positive and negative predictive values were 58% and 95% respectively. There was a fair amount of variability around the regression line which may lead to significant errors in clinical decision-making. Thus, the TcB at present has grave limitations which restrict its usefulness in the newborn.