Procoagulants and anticoagulants in fetal blood. A literature survey.

In intrauterine life, hemostasis is maintained by the same components as in extrauterine life (blood platelets, coagulation and fibrinolysis systems, involvement of the vascular wall); in the fetus, however, these components show significant differences of a quantitative/qualitative nature. In the present study, we surveyed the literature on the coagulation system in the fetus. We focused on the velocity of development of the coagulation system, being reflected in the increased concentration of all procoagulants and anticoagulants (a rise from approximately 20% in the middle of pregnancy to about 60% or more in the period of labor; exceptions: factors V, VIII and XIII which in the labor period reach the adult level) and screening test results (prothrombin time, aPTT - activated prothrombin time, and thrombin time). Reference values were given for the 19-38 weeks of pregnancy and the labor term. Biochemical features of fetal fibrinogen and PIVKA factors were also discussed. The role of activated protein C (APC) in the maintenance of balance between procoagulants and anticoagulants was postulated as well as the role of APC in the formation of thrombin activatable fibrinolysis inhibitor (TAFI)

Thrombin activatable fibrinolysis inhibitor (TAFI) in cord blood.

Thrombin activatable fibrinolysis inhibitor (TAFI) is a plasma zymogene (procarboxypeptidase B) which can decrease fibrinolysis and thus act as a haemostatic factor. TAFI is now extensively studied in many complications as well as in physiological and complicated pregnancy. The question we posed in the present study was whether TAFI antigen is present in cord blood plasma. The study group consisted of 38 parturient women, 26 primiparous and 12 multiparous with normal course of pregnancy and delivery. The cord blood was sampled from the cord vein, and the mother's blood from the antecubital vein. 3.2% sodium citrate was used as an anticoagulant. TAFIa/ai antigen was measured by ELISA method. TAFIa/ai antigen was identified in all samples of cord blood plasma. Its level was 91.50 ng/ml (range: 71.76 - 160.77 ng/ml) vs. 55.46 ng/ml (range: 39.77 - 68.54 ng/ml ) in the mother's blood, which means that the level of TAFIa/ai antigen was significantly higher in fetal blood than in maternal blood (

A comparative study of the protein C system in mother's blood, cord blood and amniotic fluid.

Activated protein C (APC) is an important anticoagulant which plays a role in pathophysiology of pregnancy, e.g. in maintenance of the uteroplacental circulation and development of the fetus as well as in pathogenesis of preeclampsia. The study objective was to compare the levels of the respective components of the protein C system (protein C, PC; protein S, PS; thrombomodulin, TM) as well as thrombin activatable fibrinolysis inhibitor - TAFI in mother's blood, cord blood and amniotic fluid. The study group consisted of 136 healthy parturients at term, divided into subgroups of 30-35. The immunoenzymatic method (ELISA) was used to measure the antigens of the components studied. The concentrations of PC and PS antigens were the highest in the mother's blood plasma (135.11+/-1.05% and 92.0+/-13.24%, respectively), lower in cord blood plasma (57.60+/-10.32% and 33.19+/-4.96%, respectively) and the lowest in amniotic fluid (6.75+/-3.50% and 2.40+/-1.64%, respectively); the differences between the levels of that of mother, fetus and amniotic fluid were statistically significant (p< or =0.0001). The TM and TAFI antigen concentrations were the highest in cord blood plasma (11.35+/-3.71 ng/ml and 91.50 (median; range: 71.76-160.77) ng/ml, respectively) and lower in maternal plasma (4.51+/-0.71 ng/ml and 55.46 - median; range: 39.77-68.54 ng/ml, respectively); the differences between the levels of that of cord blood plasma and maternal plasma were statistically significant (p< or =0.0001). Of the three protein C system components, PC and PS occur in relatively high concentrations in maternal blood, being lower in fetal blood and the lowest in amniotic fluid. On the other hand, as an exception, the concentrations of TM and TAFI are the highest in fetus blood