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Updated: Aug 14, 2026

Performing Vaginal Lavage, Crystal Violet Staining, and Vaginal Cytological Evaluation for Mouse Estrous Cycle Staging Identification
Published on: September 15, 2012
Endometrial histology and bleeding patterns in post-menopausal women taking sequential, combined estradiol and
1Department of Pathology and Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada. MDFE@MUSICA.MCGILL.CA
Objectives:
To determine the endometrial response and bleeding patterns in post-menopausal women who were given a sequential hormone replacement regimen with estradiol 2 mg and dydrogesterone 10 mg.
Methods:
One-hundred-and-eighty-eight (188) post-menopausal women with amenorrhea of 6 months or longer, with FSH/estradiol (E2) levels in the post-menopausal range and normal endometrium were entered in the study. All patients received a daily dose of 2 mg E2 during day 1-14 of each 28 day cycle and 2 mg E2 combined with 10 mg dydrogesterone during cycle day 15-28. The total duration of treatment was 12 months (13 cycles of 28 days).
Results:
The rate of adequate progestational response (secretory or atrophic) in the 146 patients who remained in the study for at least 356 days with 90% study medication compliance and received an endometrial biopsy after 13 cycles of study medication was 97.2%. Three patients had proliferative endometrium and one simple hyperplasia. Cyclic bleedings in the 153 women who remained on study medication for at least 76 days occurred in over 85% of all cycles; the day of onset occurring regularly on day 13 or 14 of the combined period; the mean duration of bleeding per cycle was approximately 5 days with most patients having (very) slight bleeding. Sixty percent of patients had no intermittent bleedings over the whole 12-month study period. The average incidence of intermittent bleeding in the remaining patients was only 2.7 and generally of very slight quantities and of short duration. Per evaluable cycle the percentage of patients with an intermittent bleeding varies from 4.6 to 9.8%. Only two patients discontinued therapy because of bleeding problems. A clear decrease in the incidence of typical menopausal symptoms, i.e. hot flushes and night sweats was observed by the first visit after 6 weeks of treatment.
Conclusions:
The endometrial safety of 2 mg E2 sequentially combined with 10 mg dydrogesterone is very good as determined by the histologic response of the endometrium. The incidence of cyclic bleedings with this combination therapy is very high as is the regularity of day of onset and duration of bleeding. Blood loss during intermittent bleedings was mild and of short duration.
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