Inherited thrombophilia can be defined as a predisposition to thrombosis caused by heritable defects, such as mutations in genes encoding the natural anticoagulants or clotting factors. Pregnancy related risk of VTE is sixfold increased comparing to non pregnant age matched women. Pregnancy is an independent risk factor for the development of venous thromboembolism and this risk is further increased by the presence of thrombophilia.
Aim of the study: The aim of the study was to evaluate the association between deficiency of natural anticoagulants: antithrombin, protein C and protein S and pregnancy related thromboembolism. We have determined the activities of antithrombin, protein C and protein S in 74 women with pregnancy related thrombosis and in 45 healthy women who had at least two uncomplicated pregnancies. Among the women with the history of venous thromboembolism antithrombin deficiency was found in 4 (5.4%), protein C deficiency in 2 (2.7%) and protein S deficiency in 5 (6.76%). The total of 11 (14.6%) women was found to be deficient. Not a single woman in the control group was found to be deficient in natural anticoagulants. Deficiencies of coagulation inhibitors are associated with an increased risk of venous thrombosis during pregnancy and puerperium (p=0.006). Antithrombin, protein C and protein S deficient women are at higher risk of developing venous thromboembolism during antepartal period (p=0.0097). Prophylactic treatment with heparin should be recommended from the very beginning of the following pregnancy in women with antithrombin, protein C or protein S deficiency.