The study of local fibrinolysis in abortion.

The etiology of abortion, which is still a moot question, is now under intense investigation. The present study discussed the possible role of local fibrinolysis (villous tissue fibrinolysis) in the pathogenesis of abortion by studying tissue fibrinolytic activity in tissue culture as well as blood coagulation, fibrinolysis and the kinin system. Subjects studied include: 1) normal villous tissue (n=46), early pregnancy loss, whose fetal cardiac activity had once been identified (n=22) designated as Group A, and Group B whose fetal cardiac activity had never been identified (n=82). The villous tissues were cultured for 24 hours and then the urokinase (UK) inhibition activity in the medium was determined. 2) Threatened abortion resulted in abortion (poor prognosis, n=42) or the pregnancy continued (good prognosis, n=81). In these patients the following substances in plasma were determined: Prekallikrein, alpha 2-plasmin inhibitor, alpha 1-antitrypsin, alpha 2-macroglobulin, C1-inactivator, antithrombin-III, plasminogen, fibrinogen, fibrin degradation products (FDP). The results are: 1) UK inhibition activity (against UK 2.5 iu), normal villous tissue 26.3 +/- 14.6%, Group A 26.0 +/- 10.3%, Group B 9.6 +/- 10.7%, a significant difference between the normal villous tissue and Group B villous tissue was observed. This suggested that the increased villous tissue fibrinolytic activity due to decreased UK inhibition activity may be one of the causes of abortion. 2) Prekallikrein was significantly reduced in patients with abdominal pain. Also, a significant reduction in plasminogen and elevated C1-inactivator was observed in patients with poor prognosis. The significance of these findings was discussed.