[The morphologic changes of endometrial hematostatic reaction in intrauterine devices induced menorrhagia]

To investigate the relationship between intrauterine contraceptive devices (IUD) induced menorrhagia and endometrial spiral arteriolar contractive function and endometrial superficial vessels thrombus formation function.

Sixty five subjects were admitted and divided into IUD bleeding group (25 cases), IUD non-bleeding group (20 cases) and IUD non-user group (20 cases). The samples were obtained by curettage within 24 hours prior to menstruation and observed under light and electron microscope. The morphologic changes of endometrial micro-vessels, spiral arterioles were observed and diameter of spiral arterioles were measured.

Compared with IUD non-user group, the degenerative changes of spiral arteriolar wall were more severe and the dilatation of spiral arteriolar lumen was obvious especially in spongious layer. In IUD non-bleeding group, these changes were mild. The platelet and fibrin thrombus count was the highest in IUD non-bleeding group and the lowest in IUD bleeding group.

These results suggested that IUD induced menorrhagia might correlated with poor contraction of spiral arterolars in spongious layer and poor thrombus formation. Mild degeneration and dilatation of spiral arterioles and a lot of thrombus were seen in IUD non-bleeding group, and this might be the cause that the mentrual blood loss in this group did not increase obviously.