Factors affecting transcutaneous bilirubin measurement: effect of daylight.

The purpose of this study was to determine whether daylight might affect the accuracy and reliability of TcB measurement at the forehead and sternum. One hundred and seven full-term newborn infants were divided into two groups. Babies in group I (N = 59) were kept near the window which was sometimes directly exposed to daylight, and babies in group II (N = 48) were kept on the door side of the room which had no direct daylight, during the first week of life. The result indicates that daylight is one of the significant factors affecting TcB measurement at the forehead, contributing to poor correlation between TcB reading at the forehead and serum bilirubin concentrations. We suggest the necessity of obtaining TcB readings at the forehead and sternum, at least, in order to improve the accuracy and reliability of such measurements in infants.