Modificaciones ultraestructurales del endometrio inducidas por dispositivos intrauterinos (DIU)

The exact nature of the mechanism of action of intrauterine devices (IUDs) is not known yet, in spite of numerous studies made to ascertain the effects of the devices. The assumption that the foreign body might induce microscopic changes capable of altering the biochemical behavior of the endometrium induced us to study the problem from the morphological viewpoint. thus, a study was performed on 20 yound IUD wearers for periods of 12 to 36 months. The IUDs used were either inert or medicated poliethylene. For this purpose, 2 mm3 samples of endometrium obtained through control biopsies were studied were studied by light microscopy and transmission (TEM) and scanning (SEM) electron microscopy. Controls were obtained from normal endometrium in either the middle or secretory stage of the cycle. The aim was to investigate ephithelial and stromal changes possibli related with the presence of inert or medicated IUDs. Light microscopy and SEM offer similar images: a flat ephithelium devoid of cilia, and areas with exfoliated epithelium, leaving the basal membrane in direct contact with the uterine cavity. An early predecidualization of the stroma is observed. Under TEM, the main changes were located in the cell organelles: decrease of microvilli, degenerative chagnes of mitochondria, vesiculation of citoplasmic membranes. In the stroma, predecidual cells and granulocytes were observed. Based on our observations it may be concluded that IUDs create unfavorable envronmental conditions for blastocystic attachment where apaprently no dislodgement of the implanted ovum occuts. Its action seems to be contraceptive rather than abortifacient in the usual sense