Etiopathology and classification of acquired coagulation disorders in the newborn infant.

In the newborn period low vitamin K dependent coagulation factors are frequently found in connection with normal global tests. To investigate this peculiar coagulation status studies were performed in 54 newborns who were divided into three groups according to their clinical course and the existence of bleeding. The results are compared to coagulation tests used for the diagnosis of disseminated intravascular coagulation (DIC). An early sign of an increased turnover of coagulation factors is a difference in the fibrinogen concentration determined by an immunological technique and a coagulation test which is sensible to fibrin(ogen)-degradation-products (FDP'S). At this stage factor II, V and VII levels are still within the normal range suggesting an increased production. In a more severe disturbance of the clotting system the increased turnover is no longer compensated by an increased production, and platelets and later on factor II and VII levels are lowered. At this early stage of DIC the vitamin K dependent factors are correlated to the factors I and V. Finally factors I and V drop as well. This stage in most infants is accompanied by the clinical symptom of bleeding. The clotting tests results are well correlated to the severity of the disease.