Which Is More Accurate: Transcutaneous Bilirubin Measurement on the Forehead or Sternum?

The accuracy and reliability of noninvasive methods of neonatal jaundice assessment are not completely obvious, including which area of the body is more suitable to estimate actual bilirubin with transcutaneous bilirubinometry (TCB).

This cross-sectional study compares the accuracy of three noninvasive methods for neonatal jaundice estimation included visual estimation, TCB on the forehead, and TCB on the sternum. The mean and standard deviation describe quantitative variables. In addition to analytical analysis, we used the linear regression test to evaluate the association of different variables with the accuracy of TCB as well as paired t test for comparing the TCB results on the sternum with the forehead before and after phototherapy. For all statistical tests, a P value less than 0.05 was considered as significant.

We enrolled 100 neonates with a mean age (±SD, standard deviation) of 6.5±1.9 days (range 2–11 days) in our study. The mean gestational age (GA) of the participants was 38.94 weeks±1.00 w SD, and their mean (±SD) weight was 3302 g (±315.60). The mean (mg/dL)±SD for bilirubin level by clinical estimation of jaundice, TCB on the forehead and TCB on the sternum were 17.35±2.88, 17.23±1.63, and 17.77±1.58, respectively. Also, comparing mean differences before and after phototherapy showed that TCB on the sternum is a good predictor for neonatal jaundice before phototherapy (0.539 vs. 0.348).

TCB on the sternum is more predictive than the forehead, especially before phototherapy, to assess the need for treatment in outpatient settings.