Publication:

Transcutaneous bilirubin measurement in preterm infants less than 35 weeks of gestation

Background Neonatal hyperbilirubinemia is a common clinical condition in preterm infants due to hepatic immaturity and increased bilirubin production. Monitoring bilirubin levels is essential to prevent bilirubin-induced neurological dysfunction. Total serum bilirubin (TSB) estimation is considered the gold standard for diagnosis and monitoring; however, repeated blood sampling in preterm infants may lead to iatrogenic blood loss, procedural pain and increased risk of infection. Transcutaneous bilirubin (TcB) measurement offers a rapid, non-invasive alternative for bilirubin estimation, but its reliability in very preterm infants requires further evaluation.

Methods A hospital-based cross-sectional study was conducted over twelve months (June 2024-July 2025) in the neonatal intensive care unit in RajaRajeswari Medical College and Hospital. Preterm infants born before 35 weeks of gestation fulfilling inclusion criteria were enrolled. Transcutaneous bilirubin measurements were obtained using a TcB device from the forehead or sternum. Blood samples for serum bilirubin estimation were collected simultaneously or shortly after TcB measurement. Data were analysed using SPSS version 23. Pearson correlation coefficient and Bland–Altman analysis was used to assess correlation and agreement between TcB and TSB values.

Results Sixty-three paired TcB and TSB measurements were analysed. The mean TcB value was 8.20±1.70 mg/dl, while the mean TSB value was 8.75±1.80 mg/dl. A strong positive correlation was observed between TcB and TSB (r=0.864, p<0.001). Bland–Altman analysis showed a mean difference of 0.546 mg/dl with acceptable limits of agreement.

Conclusions Transcutaneous bilirubin measurement demonstrates strong correlation and good agreement with serum bilirubin levels in preterm infants less than 35 weeks of gestation. TcB is a reliable non-invasive tool for monitoring neonatal jaundice and may reduce the need for frequent blood sampling in neonatal intensive care units.