Fine Structural Effects of Intrauterine Contraceptives on the Human Endometrium

Endometrial morphological changes in IUD users: a review

The introduction of an intrauterine device into the uterine cavity induces a foreign body reaction in the surrounding endometrium which is characterized by the infiltration of polymorphonuclear leucocytes and macrophages into the endometrial stroma and subsequently through the surface epithelium. Leucocyte migration is greater with copper IUDs than with inert IUDs. Ulceration of the surface epithelium, haemorrhage of erythrocytes and microthrombosis of stomach capillaries occur in the functional endometrium in contact with inert and copper IUDs. In endometrium adjacent to, but not in contact with, the IUD gaps appear in the endothelial lining of small blood vessels without a haemostatic response. The most striking response in endometrium exposed to progesterone-releasing IUDs is the occurrence of dilated, thin-walled vesicles, associated with a thinning of the surface epithelium and a decidual reaction in the stroma. A uniform suppression of the endometrium in progesterone IUD users is always found after six months of treatment, whereas the insertion of IUDs releasing 20-30 micrograms levonorgestrel induce a profound uniform suppression of the functional endometrium throughout the uterus after only four weeks.

The effects of intrauterine contraceptive devices on the ultrastructure of the endometrium in relation to bleeding complications

The effects of inert (Lippes Loop D and Dalkon Shields) and medicated (copper 7, copper T, and Progestasert) intrauterine contraceptive devices (IUDs) on the ultrastructure of the endometrium were studied in intact human uteri. The most striking morphologic changes induced by the inert and copper-bearing devices were erosion of the surface epithelium and extensive microthrombosis in stromal capillaries of the endometrium in contact with the device. These abnormalities were associated with extravascular thrombi, erythrocytes, and fibrin deposition in the adjacent stroma. Capillary microthrombosis and leukocyte infiltration into the uterine cavity were most extensive around the active part of the copper-bearing devices. With the Progestasert erosion of surface epithelium was rarely seen, but the intact epithelial lining had fewer ciliated cells with flattened and shortened cilia. Large dilated venules were a common finding below the surface epithelium adjacent to the active part of the Progestasert; capillary microthrombosis was found only below the inert arms of the Progestasert. The vascular response of the endometrium to IUDs appears, therefore, to be directly related to the type and proximity of the device. The morphologic changes induced in both surface epithelium and the microvasculature of the endometrium are the likely explanation of the uterine bleeding problems associated with IUDs but are probably intrinsic to the mode of action of the IUD in interfering with implantation.

Ultrastructural alterations in human endometrium caused by intrauterine contraceptive devices

Biopsies of endometrium from women using intrauterine contraceptive devices (IUDs) were examined by electron microscopy to elucidate the possible cause of IUD-associated uterine hemorrhage. The findings reveal the presence of degenerated, shrunken cells in the endometrial glands of IUD users. These cells, termed pyknotic or apoptotic, are more prevalent in tissue from women with complaints of excessive bleeding than in cases without such complaints. The pyknotic cells often show discontinuities of the plasma membrane at their luminal pole, from which cell contents stream into the lumen. Sometimes erythrocytes are also observed in the lumen. A second alteration in the ultrastructure of the endometrium is an abnormal increase in microfilaments in the epithelial cells. These two changes, a large number of pyknotic cells on the one hand and increase in microfilaments on the other, are correlated with excessive bleeding but they do not explain in simple terms of outflow of erythrocytes. Probably some inflammatory mechanism is involved. The increased number of microfilaments might be helping the movement of fluid from healthy to pyknotic cells.

The response of endometrial blood vessels to intrauterine contraceptive devices: an electron microscopic study

The ultrastructure of the vascular supply of the endometrium in uteri containing inert and copper bearing intrauterine contraceptive devices (IUCDs) has been compared with that in uteri removed at comparable stages of the menstrual cycle for dysfunctional uterine bleeding. In the endometrium from all uteri containing inert and copper IUCDs, stromal capillaries below the devices showed extensive microthrombosis with platelet and fibrin aggregations filling gaps in the endothelial linings of the vessels. Considerable stromal haemorrhage and erosion of surface epithelium was associated with this vascular pathology. In the uteri removed for dysfunctional bleeding, microthrombosis was a rare occurrence. In the stromal vessels of the endometrium not in contact with the devices, the surface epithelium was usually intact and the underlying stromal capillaries often showed breaks in the endothelial lining but without a haemostatic plug. Leucocyte migration into the stroma was more evident in association with the copper IUCDs than the other devices. The ultrastructural changes in the microvasculature of the endometrium associated with IUCDs did not appear to be related to a stage of the menstrual cycle. The extent and type of microvascular changes appeared to be related to the proximity and surface area of the IUCD and to the presence or absence of copper in the device.

Morphologic studies on IUD-induced metrorrhagia. II. Surface changes of the endometrium and microscopic localization of bleeding sites

Surface changes were extensively studied by light and electron microscopy in human endometrium exposed to IUD's. A wide variety of alterations in the covering epithelium and its basal lamina (basement membrane) was observed. These ranged from essentially no alteration to a covering basement membrane completely denuded of its epithelium. Erosions or discontinuities of the surface basement membrane were uncommon, and when they occurred were most often associated with extrusion of fluid and cellular elements from the stroma into the uterine lumen. Metrorrhagia associated with IUDs probably results from two basic types of hemorrhage through the endometrial surface. Tissue adjacent to the IUD with interstitial hemorrhage bleed into the uterine cavity by (1) red cell transmigration through surface membranes (surface epithelium and its basal lamina), and (2) high interstitial pressure breaks in these same membranes.

Intra-uterine devices, A SEM study on the Dalkon Shield

A SEM study carried on intra-uterine devices (Dalkon Shield) is reported. The poor manufacturing of the devices is stressed, which could increase their efficiency but also the risks of penetration, or worse, perforation. The solution for the future could be copper bearing intra-uterine devices coated by hydrogels. This should maintain efficiency and improve security.

Comparative studies of the ethynyl estrogens used in oral contraceptives. I. Endometrial response

Reproductive-age women were given identically prepared mestranol or ethynylestradiol orally for two consecutive 21 day cycles in doses ranging from 50 to 100 mug per day. Endometrial biopsies were obtained at the end of the second cycle and assessed for estrogenic effect. At these dose levels and with this treatment regimen, no differences could be detected between doses or between drugs, indicating that a plateau in endometrial response was reached.

Endometrial morphology in women exposed to uterine systems releasing progesterone

A blind study was done in 402 endometrial biopsies of women who had intrauterine devices releasing different daily amounts of progesterone or a placebo (empty device): 175 were obtained in what presumably was the proliferative phase and 227 in the secretory stage, as all these subjects were normal, healthy women with a history of previous fertility. With all dose levels of the progesterone-releasing devices there was variation of the endometrium general pattern and the over-all picture varied from normal secretory to suppressed endometrium. In addition to these changes of the endometrial pattern, in 231 specimens there was significant inflammatory infiltration and in six cases even plasma cells were seen. Predecidual reaction was frequently seen and in 45 cases it was diffuse and marked. The significance of these data is discussed on the grounds of the frequent similarities of the changes here reported with those in women using combined oral steroids for contraception.