CHANGES IN THE WITHDRAWAL BLEEDING PATTERN AND ENDOMETRIAL HISTOLOGY DURING 17-BETA-ESTRADIOL DYDROGESTERONE THERAPY IN POSTMENOPAUSAL WOMEN - A 2-YEAR PROSPECTIVE-STUDY

To describe changes in the withdrawal bleeding pattern and endometrial histology during a sequential 17 beta-estradiol - dydrogesterone regi men in postmenopausal women. Design: Open-label, non-comparative, pros pective study. Setting: Gynecological outpatient department of a unive rsity hospital. Patients: Twenty-seven healthy nonhysterectomized post menopausal women, Interventions: Continuous micronized 17 beta-estradi ol supplementation 2 mg daily, and cyclic administration of dydrogeste rone, 10 mg daily for the first half of each 28 day treatment cycle. M ain Outcome Measures: Changes in the characteristics of the withdrawal bleeding pattern and the endometrial biopsy histology during 2 years of treatment. Results: The initial withdrawal bleeding was comparable to normal menstruation with respect to amount and duration. During the 2 years of treatment the bleeding showed a significant tendency to be come shorter with less blood loss. This was mainly the result of the d ecrease (P < 0.001) in the number of days per cycle with bleeding grad e II (normal menstruation). None of the women developed endometrial hy perplasia, and in almost all women the given hormone replacement thera py regimen induced secretory or atrophic changes of the endometrium. C onclusions: This sequential 17 beta-estradiol - dydrogesterone regimen can be regarded as safe with respect to the prevention of endometrial disease and appeared to foster patient compliance.