The Haemostatic Mechanism and Menstruation: The Role of Intra-Uterine Contraceptive Devices.

The haemostatic mechanism of 40 female patients undergoing menstruation, 20 with intra-uterine devices (IUCD) and 20 without (Control), were studied. The patients' coagulation profiles, fibrinolytic system and platelet functions were studied before and after hysterectomy. Platelet survival times and platelet consumption was determined using Cr. labelled autologous platelets. Patients who menstruated during the study had their pads collected and radioactivity measured. Histology, autoradiography and scintillation counting was performed on uteri obtained from a hysterectomy performed towards the end of the platelet survival study period. There were no significant differences in the coagulation, fibrinolytic and platelet function tests in these 2 groups, though in each group there were the expected changes after operation.Platelet survival time, consumption and radioactivity in the tampons showed no significant differences between the IUCD and control groups, although there were 6 patients with low platelet survival times in the IUCD group. Resected uteri showed surprising lack of concentration of platelets which may have been due in part to loss of blood at operation and handling of the uterus. Surprisingly, in the control patients, platelet survival time in response to the severe haemosatic challenge of menstruation were normal. However in the IUCD group, 6 patients showed shortening of platelet survival. Also surprisingly and equally in both control and IUCD groups, was the small amount of platelet related radioactivity in the menstruating fluid.