[Clinical and morphological studies in patients with a progesterone-releasing intrauterine contraceptive device (Progestasert-System) (author's transl)].

We studied in twenty women the effectiveness of a new type of intrauterine device, which is coated with progesterone. Since the progesterone-coating is estimated to last one year, we studied the women for that period of time. None of them became pregnant. Most complained of some disturbances of menstrual bleeding during the first three months. A few experienced these disturbances for the whole year of observation. No other side effects developed like those experienced with oral contraceptives. Six hysterectomy specimens and one complete curettage became available for us to examine the histological changes produced by this new type of intrauterine device. The endometrium in all revealed a distinct division into two horizontal layers produced by progesterone absorbed from the device. The upper layer of endometrium next to the device showed a decidual change with sparse atrophic glands, like those of an arrested secretion. The underlying layer exhibited either normal proliferative or secretory changes consistent with the phase of the menstrual cycle. The remarkably circumscribed decidual change led us to refer to it as "perifocal arrested secretion", a term emphasizing that the gestagen inserted into the uterine cavity acts locally on the endometrium. Foci of endometrium in the myometrium (adenomyosis) are not affected.