Correlation between transcutaneous and serum bilirubin in preterm infants before, during, and after phototherapy.

BACKGROUND

Transcutaneous bilirubinometry (TcB) is routinely used to monitor jaundice in term and near-term infants. However, before 35 weeks gestation, the technique has not been widely adopted.

AIM: The aim of this study is to study the correlation between TcB and total serum bilirubin (TsB) before, during, and after phototherapy in preterm infants born before 35 weeks' gestation.

METHODS

Jaundice was monitored in infants born before 35 weeks' gestation by simultaneous measurements of TsB and TcB assessed by a Drager Jaundice Meter JM-103 (Draeger Medical, Inc., Telford, PA).

RESULTS

About 588 pairs of measurements were recorded in 86 premature infants of 26-34 weeks, weighing 618-2400 grams. The overall correlation coefficient between TcB and TsB was 0.8 (p = .001). Subset analysis revealed lower correlation in infants born before 30 weeks. TcB was consistently estimated around 1 mg% lower than TsB. Neither the cause of the jaundice nor major neonatal morbidities significantly influenced the TcB-TsB correlation.

CONCLUSIONS

TcB is a reliable measure of jaundice before 35 weeks' gestation with a mean under-estimation of ≈1 mg%. TcB use may reduce unnecessary invasive blood tests.