Biochemical tissue-specific injury markers of the heart and brain in postpartum cord blood

OBJECTIVE: We sought to establish references ranges and to test the hypothesis that biochemical tissue-specific markers for the heart in umbilical cord blood of newborns with cardiac defects and intrauterine growth restriction (IUGR) are abnormal. STUDY DESIGN: A prospective study was conducted. Serum samples of the umbilical vein (n = 280) and artery (n = 156) from 599 healthy newborns at 37(+0)-42(+0) weeks of gestation were collected. Total creatine kinase (CK), CK-MB heart type (CK-MB), cardiac troponin T (cTnT), myoglobin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and S100 were measured. Reference ranges for each marker were constructed. Concentrations of tissue-specific markers from umbilical cord blood of neonates with cardiac defects (n = 10) and IUGR (n = 41) were plotted against the established reference ranges. RESULTS: Reference ranges for each studied marker were established for both umbilical artery and vein. In fetuses with cardiac defects, both NT-proBNP (4/6 [66%] in the artery, 7/10 [70%] in the vein) and cTnT (2/10 [20%] in the vein) were increased. In fetuses with IUGR in the vein, NT-proBNP (10/41 [24%]) and cTnT (5/41 [12%]) were increased, whereas S100 (9/41 [21%]) was decreased. CONCLUSION: In a subset of neonates with cardiac defects or growth restriction, irrespective of the pH at birth, tissue-specific injury markers for the heart in umbilical cord blood are abnormal.