INTRAUTERINE AND SUBDERMAL PROGESTIN ADMINISTRATION IN POSTMENOPAUSALHORMONE REPLACEMENT THERAPY

Objective: To compare the effects of intrauterine and subdermal admini stration of levonorgestrel on control of bleeding and on the endometri um in postmenopausal hormone replacement therapy. Interventions: Ninet een women started continuous oral E(2) valerate therapy (2 mg daily) t ogether with continuous parenteral progestin therapy. The subjects ran domly received either a subdermal levonorgestrel-releasing implant (n = 9) or an intrauterine device (IUD) releasing levonorgestrel (n = 10) . Main Outcome Measures: Serum concentrations of estrone, E(2), FSH, s ex hormone-binding globulin (SHBG) and levonorgestrel were followed. E ndometrial biopsies and transvaginal ultrasonography were used to eval uate the endometrium. The subjects kept daily records of bleeding. The observation time was 1 year. Results: Serum concentrations of the hor mones mentioned above and SHBG were similar in both groups during the observation time, but the patterns of bleeding differed. In the IUD gr oup there were 0.9 days (mean, range 0 to 4 days) of spotting and no d ays of bleeding during the last month of the follow-up year. In the im plant group there were 8 days (mean, range 0 to 25 days) of spotting a nd 3.4 days (mean, range 0 to 14 days) of bleeding. In histological ex amination there was uniform atrophy in the endometrial samples from th e IUD group, and a weak or absent progestin effect in the implant grou p. Conclusions: In spite of similar serum levonorgestrel concentration s, local intrauterine administration of levonorgestrel resulted in bet ter control of bleeding and in more effective endometrial suppression than subdermal administration.