Transcutaneous bilirubin measurement in healthy Saudi term newborns

I read with interest the study by Alsaedi1 on the transcutaneous bilirubin (TcB) measurement in healthy Saudi term newborns. The author addressed that TcB measurement provided accurate estimates of total serum bilirubin (TSB) values and it can be used effectively to screen newborns for significant jaundice.1 I presume that such conclusion ought to be cautiously taken. Apart from 4 limitations addressed by the author, I presume that the following 4 points might be additionally contributory and they could cast suspicions on the accuracy of the study results and hence, the implication in the clinical setting. 1) In the methodology, the author mentioned that BiliCheck device displayed the average in micromole/l of 5 measurements from different areas of the forehead for each bilirubin.1 Recently published studies have shown that measurement of transcutaneous bilirubin on the sternum had higher accuracy as compared to serum bilirubin measurement on the forehead.2,3 2) There are numerous different transcutaneous bilirubinometers (TcBm) in the clinical setting to estimate TcB. Comparative studies have shown varied agreement of TcBm with each other and TSB.4-6 3) The author addressed that the study was conducted in the western region of Kingdom of Saudi Arabia with a population of diverse ethnic backgrounds and various degree of skin pigmentation.1 I presume that the different racial backgrounds of the studied population could alter the precision of the study results as it has been noticed that the race could affect TcB bias when measurements were carried out on the forehead, but not when they were carried out on the sternum.7 4) Better interpretation of TcB measurement in the neonatal clinical setting is based on an hour-specific, percentile-based TcB nomogram.8 To my knowledge, such nomogram is not yet constructed during the early neonatal period for Saudi neonates. Despite the aforementioned limitations, I think that TcB measurement represents a revolutionary step in the management of neonatal jaundice as it is associated with less pain related to heel prick as well as 55% reduction in blood samples taken in jaundiced term and near-term babies.9