Fibrinolytic activity of menstrual blood in normal and menorrhagic women and in women wearing the Lippes Loop and the Cu-T (200).

Assessment was made of the fibrinolytic activity in menstrual and peripheral blood of 30 normally menstruating and 30 menorrhagic patients and of 30 women wearing Lippes Loops and 15 wearing CU-T (200)s. Assessment was performed by measuring the area of lysis on heated and unheated fibrin plates. Also, histochemical identification of fibrin fibrils in the menstrual endometrium was performed by Mallory's phosphotungstic acid hematoxylin method. Results in the normally menstruating group were compared to those of the menorrhagic women, and together these were compared with results in the groups of women wearing intrauterine devices. The fibrinolytic activity in menstrual blood was significantly increased in menorrhagic patients compared to that in normally menstruating patients, but no significant difference was detected in the plasma of either group. The histochemical study of the normally menstruating endometrium revealed dense intravascular and extravascular deposits of fibrin. Less dense intravascular fibrin deposits, but no extravascular ones, were present in the menorrhagic patients. The increase in the fibrinolytic activity of menstrual blood and the decrease in the density of fibrin deposits in the menstrual endometrium of the menorrhagic women were thus associated and were probably involved in the excessive menstrual loss. The fibrinolytic activity of menstrual blood in women wearing Lippes Loops was higher than that in women with Cu-T (200)s and was associated with decreased density of fibrin fibrils in the menstruating endometrium. This may explain the increased blood loss associated with the use of the Lippes Loop.