Transcutaneous bilirubinometry in the management of bilirubinemia in term neonates.

One hundred full term babies of both sexes were randomly selected for transcutaneous bilirubin index (TcBI) estimation at the forehead at 12-24 h intervals from the time of appearance of clinical jaundice till the serum bilirubin levels fell within safe limits. TcBI was correlated with serum bilirubin estimated by conventional diazo method. Forty babies required phototherapy, in 20 an area of 2.5 cm2 over the forehead was covered during phototherapy to make an unexposed 'window' for TcBI estimation. The other 20 newborns received phototherapy as such and TcBI was estimated on the forehead. There was a linear relationship between serum bilirubin level and TcBI estimated at the forehead (r = 0.9090; P < 0.001). Further a significant linear correlation between prephototherapy and post-phototherapy (covered and uncovered groups) TcBI and serum bilirubin levels also existed (r = 0.7979; P < 0.001). There was no significant difference between post-phototherapy TcBI estimated at the covered and uncovered areas of forehead. However, post-phototherapy values of TcBI were significantly lower than corresponding prephototherapy values at higher serum bilirubin levels (> 16 mg/dl).