Thrombin generation test as a marker for high risk venous thrombosis pregnancies

Pregnancy is a well-established risk factor for venous thromboembolism and is associated with a state of hypercoagulability. The use of sensitive and specific biological markers to predict risk factors for thrombosis is essential during pregnancy. Our objective was to investigate the usefulness of thrombin generation test (TGT) as a marker to predict the risk of thrombosis in high risk venous thrombosis (HRVT) pregnancies compared to normal pregnancies. This retrospective study enrolled 134 women with HRVT pregnancies, 78 of whom had monozygotic, spontaneous and untreated pregnancies and formed the study group. The control group comprised 106 women with normal pregnancies. Routine assessment of coagulation activation markers: fibrinogen, d-dimer, prothrombin fragments 1 + 2 (F1 + 2), thrombin-antithrombin complexes (TAT) and fibrin monomer complexes (FMC) was performed every 5 weeks in the study group to detect a possible pathological state of hypercoagulability. TGT was performed using platelet-free plasma, 1 and 5 pM tissue factor (TF), supplemented by phospholipids (PL) ± thrombomodulin. Fibrinogen, d-dimer, F1 + 2, and TAT, but not FMC, increased significantly throughout pregnancy in both groups but no difference was shown between the groups. TGT showed an early increase in thrombin generation in both groups, which stabilized during the second month of pregnancy. No correlation was demonstrated between thrombin generation parameters and coagulation activation markers. Based on our results, TGT did not prove conclusive as a marker to predict the risk of thrombosis in HRVT pregnancies. Finding a sensitive and specific biological marker to predict thrombosis risk requires further investigation.