Molecular markers of the endothelium, the coagulation and the fibrinolytic systems in healthy newborns.

Endothelium derived substances may play a role in the physiological adaptation processes at the time of birth. The aim of this study was to investigate plasma concentrations of activation markers of the endothelium (endothelin-1, thrombomodulin, von Willebrand factor), of the coagulation and the fibrinolytic systems (thrombin-antithrombin III complex, D-dimer, plasmin-alpha2-antiplasmin complex) during the first days of life. Venous blood from peripheral veins was collected from 79 healthy newborns and for comparison from 38 healthy infants and schoolchildren, as well as from 17 healthy adults. Except for endothelin and von Willebrand factor, the concentrations of activation markers were significantly higher in the newborn group. During the first 12 days of life thrombomodulin, thrombin-antithrombin III complex, and plasmin-alpha2-antiplasmin complexes showed a continuous decline whereas the concentrations of endothelin, von Willebrand factor and D-dimer did not change. The highest D-dimer concentrations were found at low umbilical arterial pH and after birth by vaginal operation suggesting an influence of birth stress. Thrombomodulin was correlated with endothelin (r=+0.471) and with von Willebrand factor (r=-0.415). In conclusion, endothelial, coagulation, and fibrinolytic systems are activated in newborns which might occur during birth by the mechanical stress, the adaptation of circulation, and the short-term hypoxic state. An additional intrauterine activation should also be considered.