A common procedure for the diagnosis of hyperbilirubinemia is the total investigation of total serum bilirubin (TSB); however, this procedure is invasive for neonates. For two decades, transcutaneous bilirubin (TCB) was used as a non-invasive and painless method to assess bilirubin.

This study aimed to compare the accuracy of TCB versus TSB before and after phototherapy.

This descriptive-analytical study included 85 neonates. Neonates were selected by convenience sampling methods. Neonates had a normal birth weight and physiological jaundice; having no need for blood transfusions. Data were collected using a BiliChek device (APEL, Japan). The researcher, before phototherapy and simultaneously by checking the TSB, pressed the BiliChek three consecutive times in the middle of the neonate’s forehead and then, recorded the results. The correlation between TCB and TSB were determined before and after phototherapy. Pearson, t-test, and ROC were used by SPSS v.18 for analysis data.

There was a strong correlation between the TCB and the TSB in neonates weighing 3001 to 4000g before phototherapy (r = 0.74, P < 0.001). Although, there was a low correlation between the TCB and the TSB in these neonates after phototherapy (r = 0.40, P > 0.05), the cut-off value of bilirubin was 6 - 8 mg/dL. The sensitivity was (100%) and specificity was 90% for bilirubin at the levels of 6.7 mg/dL.

TCB procedure can be a reliable alternative to the TSB, especially in the initiation of phototherapy with bilirubin levels of 6 - 8 mg/dL. However, it is not a device with a high accuracy after phototherapy.