Validity of Umbilical Cord Blood Procalcitonin in the Diagnosis of Early-Onset Neonatal Infection

Abstract

Introduction: Early-onset neonatal infection (EONI) poses significant risks to neonatal health, necessitating reliable diagnostic markers for early detection. This study aims to evaluate the diagnostic validity of procalcitonin (PCT) concentration in umbilical cord blood as a biomarker for EONI. Methods: This prospective study was conducted at Ho Chi Minh University Medical Center from April 2022 to September 2022. The PCT level was measured in umbilical cord blood at birth. Based on clinical, laboratory, and microbiologic results, neonates were classified into infected and non-infected groups. Results: One hundred eighty neonates with risk factors for EONI were recruited. Among the neonates studied, 22 (12.2%) were classified as infected and 158 (87.8%) as non-infected by the classification criteria of clinical manifestations, laboratory tests, and blood culture. The median PCT in the infected group was significantly higher than that in the non-infected group (0.389 ng/mL vs. 0.127 ng/mL, p = 0.007). The optimal PCT cut-off was found by receiver operating characteristic (ROC) to be 0.23 ng/mL, with an area under the curve (AUC) of 0.87. The results were 59.1%, 98.7%, 86.2%, 94%, 45, and 0.41 for sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios, respectively. The post-test probability was 86% if the test was positive and 5% if it was negative. Conclusion: Umbilical cord blood PCT might be a reliable marker in the diagnosis of EONI, and its value helps limit the harmful effects of unnecessary prescriptions in non-infected neonates. However, considering the low sensitivity of procalcitonin, further research is necessary to fully integrate this biomarker into clinical practice.