Cardiac troponin I, cardiac troponin T and creatine kinase MB concentrations in umbilical cord blood of healthy term neonates

Aims: To measure and compare cardiac troponin I, cardiac troponin T and creatine kinase MB concentrations in the umbilical cord blood of healthy term infants and to investigate the relationship between maternal and neonatal troponin values at birth. Methods: Troponin I, troponin T and creatine kinase MB concentrations were measured from the umbilical cord samples of 85 healthy term neonates and in the blood samples of their respective mothers at birth. Results: Median (interquartile range) umbilical cord concentrations were 0 mug/L (0-0) for troponin I, 0 mug/L (0-0.019) for troponin T and 4.90 mug/L (3.90-6.61) for creatine kinase MB. Troponin I and T concentrations were higher than the detection limit for the assay in 2 (2.3%) and 41 (48.2%) neonates, respectively. Two mothers ( 2.3%) had cTnT levels above the detection limit; none of them had increased levels of cTnI. Conclusion: Probably owing to differences in expression and assay detection limits, cord blood troponin T concentrations are frequently over the detection limit at birth, while troponin I is mostly undetectable and comparable with that in healthy pregnant women. These cardiac regulatory proteins are of neonatal origin and are not influenced by maternal levels.