Publication:

Correlation of cord blood alkaline phosphatase level with serum bilirubin level in term neonates with jaundice: an observational study

Background Neonatal hyperbilirubinemia remains a significant concern in neonatal care, affecting newborn health and requiring early identification for timely intervention.

Methods This observational study was conducted in the Department of Pediatrics at Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, from July 2024 to December 2025. A total of 145 term inborn neonates were enrolled. Cord blood samples were collected at birth for estimation of alkaline phosphatase (ALP) levels. Neonates were followed up for the first 5 d of life with daily transcutaneous bilirubin monitoring, and serum bilirubin estimation was performed when indicated. Statistical analysis included Spearman’s correlation and receiver operating characteristic (ROC) curve analysis. Sensitivity, specificity, and predictive values were calculated.

Results Cord blood ALP levels showed a moderate positive correlation with maximum serum bilirubin levels (ρ=0.541, p=0.001). Of the 145 neonates, 33 (22.8%) required phototherapy. Roc analysis demonstrated fair predictive ability of alp for phototherapy requirement (auc=0.695). The optimal cut-off value of 117.5 u/l yielded sensitivity of 51.85%, specificity of 84.85%, positive predictive value of 91.80%, and negative predictive value of 35.0%.

Conclusions Cord blood alp is a simple, non-invasive, and cost-effective biomarker that correlates significantly with serum bilirubin levels. It may be useful for early identification of neonates at risk of hyperbilirubinemia, enabling timely monitoring and intervention, particularly in resource-limited settings.