Increase of plasma tissue-plasminogen activator antigen levels after induced abortion.

We previously reported that plasma thrombotic activity is transiently increased immediately after induced abortion. However, changes in the fibrinolytic system have not yet been studied. Plasma tissue-plasminogen activator (t-PA) antigen levels were studied before and after abortion induced during the first trimester of pregnancy. Compared with the preoperative level (1.68 +/- 0.15 ng/ml), t-PA level was significantly increased (2.78 +/- 0.55 ng/ml, p less than 0.01) 15 min after the induced abortion, while it almost returned to the preoperative values (2.09 +/- 0.40 ng/ml) 2h later. This finding suggests that fibrinolytic activity is transiently increased immediately after the induced abortion, acting as a defense mechanism against thrombosis.