Examination of certain coagulation factors in menstrual fluid from women with normal blood loss

Examination of coagulation factors in menstrual fluid collected from women with normal menstrual blood less (less than 80 ml) showed the absence of thrombin generating enzymes. Factor X, pro-thrombin and free thrombin were absent from menstrual fluid. No difference was found between days 1 and 2 of menstruation. Thus activation of coagulation enzymes occurs during normal menstruation though the menstrual blood is characteristically fluid.