Effect of intrauterine contraceptive device on uterine haemostasis: a morphological study

The effect of the intrauterine contraceptive device (IUCD) on uterine haemostasis was studied at various stages of the menstrual cycle in a series of 46 patients by light- and electron-microscopy and by following the distribution of an infusion of 51Cr-labelled autologous platelets. The endometrium in contact with the IUCD in the majority of cases showed grooving with atrophy and mild chronic inflammation in the surrounding tissues. The adjacent stroma also showed increased vascularity and occasional foci of haemorrhage but the increased blood loss associated with the presence of the IUCD could not be attributed to mechanical erosion or stromal blood vessels by the device. During menstruation the presence of an IUCD does not appear to inhibit the formation of fibrin/platelet thrombi although both in control and IUCD patients there was a striking paucity of platelet/fibrin thrombi in circumstances where their formation should be enhanced. In contrast to other workers we have not observed that gaps or breaks in the endothelial lining of endometrial blood vessels occur with any greater frequency in patients fitted with an IUCD. The principal mechanism by which uterine haemostasis is achieved remains to be established.