Comparison of Serum Bilirubin with Transcutaneous Bilirubinometry in Late Preterm and Term Newborn

Abstract

Neonatal jaundice or hyperbilirubinemia is a common occurrence in newborns. It can progress to develop kernicterus unless intervention is initiated. Severity and decision for management are usually based on serum bilirubin which needs blood sampling. Transcutaneous bilirubin measurement is a noninvasive technique and correlates closely with serum bilirubin. This Cross sectional study was done in the Department of Neonatology, Bangabandhu Sheikh Mujib Medical University from March 2013 to August 2014 to evaluate the transcutaneous bilirubin in comparison to serum bilirubin. Total 160 infants with ≥35 weeks were purposively included over a period of 16 months. Neonates with less than 35 weeks, previously exposed to phototherapy, serious illness which leads to impaired circulation, who have had exchange transfusion, having major congenital malformation were excluded. Transcutaneous bilirubin measurement was performed within 30 minutes of obtaining sample for total serum bilirubin measurements. Of the enrolled infants, mean birth weight was 2631±520 grams, postnatal age was 4.99±3.02 days ranging from 2 to 25 days and mean transcutaneous bilirubin and serum bilirubin value was 14.59±2.55 and 13.62±2.86mg/dl respectively. Mean difference of transcutaneous bilirubin and serum bilirubin was 0.97±1.01mg/dl. In the total enrolled infant, transcutaneous bilirubin and serum bilirubin values showed significant correlation (r = 0.93, r2 = 0.876, p<0.001) and this was not affected by sex, gestational age, postnatal age, and birth weight. The area under ROC curve for transcutaneous bilirubin was 87% (p value <0.001). If the cut off value of transcutaneous bilirubin was set at 15 mg/dl, then a sensitivity of 77%, specificity of 88% and accuracy of 82% were obtained. Use of transcutaneous bilirubin can reduce need for serum bilirubin in assaying neonatal jaundice; as it showed significantly high correlation with serum bilirubin. Predictive accuracy of transcutaneous bilirubin was found to be statistically significant in comparison to serum bilirubin.