Serum levels of coagulation-fibrinolysis factors in normal pregnancy, labor and puerperium and in cesarean section delivery.

Plasma levels of fibrinopeptide A (FPA), fibrinopeptide B beta 15-42 (FPB beta 15-42), high molecular weight kininogen (HMW-kg), kinin, prekallikrein and kallikrein inhibitor during pregnancy, labor, cesarean section and puerperium were studied in 170 cases of full term normal delivery and 20 cases of cesarean section delivery with 30 non-pregnant women taken as control. Significant increases of FPA, FPB beta 15-42 and kinin during normal delivery and puerperium were found. There was also a significant increase of FPA in the uterine venous blood during cesarean section. Significant decrease of HMW-kg during normal labor and also significant decrease of prekallikrein and kallikrein inhibitor after cesarean section were also seen. Our findings suggested that the hypercoagulable state during pregnancy is due to the increase of thrombin and plasmin activity, and the kallikrein-kinin system may be related to the onset of labor and post-delivery uterine contraction. Increase of the FPA in the uterine blood promoted localised coagulation activity during cesarean section.