[Assessment of the hemostatic system in healthy preterm and fullterm newborns].

Assessment of the hemostatic system in premature and newborn infants. When the newborn is compared to older children and adults, several differences in the coagulation and fibrinolytic systems have been described; near-adult values are achieved for most components by 6 months of life. The newborn has an impaired platelet aggregation, reduced synthesis of clotting factors and inhibitors and molecular abnormalities in some proteins of blood coagulation. The role of fibrinolysis is, however, less well known. We have performed a study to assess the fibrinolytic activity in 100 healthy newborns and we have found a marked increase of the fibrinolytic activity, mainly related to an enhancement of plasminogen activators (t-PA) and reduction of fibrinolysis inhibitors, without systemic fibrinolysis. These results would suggest that the fibrinolytic system in the newborn is in equilibrium with the clotting system in order to preserve physiological hemostasis.