Clinical applications of fibrinolytic inhibition in gynaecology.

'In healthy menstruation the blood which is discharged does not coagulate; in the irregular or unhealthy it does....' This observation on the non-coagulability of menstrual blood was made by John Hunter in 1794.1 A similar observation was made by Bell in 19122 on the composition of menstrual blood found in patients with haematocolpos. Over the past 20 years laboratory and clinical research has established that fibrinolysis is intimately concerned with the process of menstruation. The early studies of plasminogen activator showed high concentrations present in both the uterus and menstrual discharge.3 4 Extracts of secretory endometrium and endometrium from women with endometrial hyperplasia contained large amounts of activator. This established that the fluidity of menstrual blood was due to fibrin dissolution by plasmin produced by the activators of plasminogen. In a review offibrinolysis Astrup5 suggested that increased local fibrinolytic activity might be the cause of excessive menstrual bleeding. This was supported by the findings of high concentrations of tissue activator in the fibrinolytic enzyme system not only in the endometrium but also in the myometrium of the uterus and in the glands of the cervical canal.6 7 In a study of patients with excessive menstrual loss measured by an objective method, Rybo in 19668 reported that the concentration of plasminogen activators in the endometrium was significantly higher than in women with normal menstrual loss. He also reported that the concentration increased in the premenstrual phase and was highest at the beginning of menstruation. High concentrations of fibrin/fibrinogen degradation products (FDP) are present in menstrual blood9 but no difference is found whether menstrual loss is normal or excessive. Basu'0 reported raised serum FDP levels in women with menorrhagia but others have found no relationship between the FDP level and the amount of menstrual loss.1" Indications for fibrinolytic-inhibitor treatment