Changes in activity of plasma thrombin activatable fibrinolysis inhibitor in pregnancy

The thrombin activatable fibrinolysis inhibitor (TAFI) is a recently described inhibitor of fibrinolysis. Changes in the concentration of plasma TAFI molecules that are present and functional after activation by thrombin-thrombomodulin complex (TAFI activity) during pregnancy have not previously been studied, and we therefore conducted a present prospective study. Plasma TAFI activity was assayed in 15 healthy non-pregnant women and 176 healthy pregnant women at various stages of gestation. TAFI activity was higher in pregnant than in non-pregnant women. TAFI activity seemed to increase progressively until around 20 weeks of gestation, then maintained a moderately elevated level until delivery, and promptly decreased after delivery.