Thrombin-antithrombin III Complex and Plasmin-α2 plasmin inhibitor Complex during Pregnancy

We studied the changes of thrombin-antithrombin III complex (TAT) and plasmin-α2 plasmin inhibitor complex (PIC) levels during pregnancy, and evaluated the clinical implications of TAT and PIC levels in pregnant women with obstetric past history of miscarriage or stillibirth, those with various obstetric troubles for the first time in the present pregnancy, and those with toxemia. In normal pregnancy the TAT levels increased at term (less than 20ng/mL), but the PIC levels did not (lower than 0.8μg/mL). Many patients with toxemia showed an increase in TAT and PIC, and the elevation of PIC was marked as compared with normal pregnancy. Four of 8 patients (50%) with missed abortion and intrauterine fetal death showed elevated TAT, whereas increased PIC was observed in two of 8 (25%). TAT and PIC levels of the patients with other obstetric troubles did not show significant change. We conclude that pregnant women are in hypercoagulable state rather than in hyperfibrinolysis. Further studies are needed with more careful and frequent venipunctures to clarify whether TAT is a predictor for missed abortion and intrauterine fetal death, and elevated PIC is related to toxemia of pregnancy.