ENDOMETRIAL HISTOLOGY, UTERINE BLEEDING, AND METABOLIC CHANGES IN POSTMENOPAUSAL WOMEN USING A PROGESTERONE-RELEASING INTRAUTERINE-DEVICE AND ORAL CONJUGATED ESTROGENS FOR HORMONE REPLACEMENT THERAPY

Seven normal postmenopausal volunteers were enrolled in an 18-month st udy to evaluate a progesterone-releasing intrauterine device (P-IUD) u sed in conjunction with oral conjugated estrogen to control uterine bl eeding and inhibit the endometrial effect of estrogen. Serum estradiol (E(2)) levels were elevated over baseline in all women throughout the course of the study. Serum progesterone (P-4) did not change signific antly after the insertion of the P-IUD. Endometrial thickness by ultra sound was <9.0 mm throughout the course of the study. Endometrial hist ology was interpreted as marked progesterone effect (decidualization) in all of the endometrial biopsies obtained at 6, 12, and 18 months. U terine bleeding was infrequent after the third month after insertion o f the P-IUD in all but one of the volunteers. Serum lipids obtained at 6 and 12 months showed an increase in triglycerides between these two intervals but no change in serum cholesterol. Two of the six voluntee rs had a decrease in HDL(2) cholesterol, which is unexplained. Bone de nsitometry determinations of the lumbar spine and femoral neck showed an increase during the course of the study. The P-IUD was acceptable t o the volunteers, and based on these data, appears effective in inhibi ting the estrogen effect on the endometrium and reducing uterine bleed ing. These attributes make targeting delivery of progesterone to the e ndometrium an attractive method for hormone replacement therapy.