Transvaginal ultrasonographic assessment of the endometrium in asymptomatic, postmenopausal women using different HRT regimens containing tibolone or estrogen.

Abstract

OBJECTIVE: To assess the effects of hormone replacement therapy (HRT) on endometrial thickness as measured by transvaginal ultrasonography in asymptomatic, postmenopausal women. STUDY DESIGN: Between 1997 and 2001, 307 women who had no risk factors for endometrial cancer or abnormal vaginal bleeding were enrolled in a study. Patients received 1 of the following HRT modalities: (1) oral equine HRT modalities: (1) oral equine estrogen, (2) oral 17beta-estrogen, (3) transdermal 17beta-estrogen, or (4) oral tibolone. All women taking estrogens were also taking a progestin. Only the patients with endometrial thickness >7 mm underwent endometrial biopsy while taking HRT. RESULTS: Although we observed an increase in serum estrogen levels as compared to the levels before tibolone therapy, changes in endometrial thickness were not statistically significant in patients taking tibolone. CONCLUSION: Endometrial thickness with tibolone closely mimics the naturally atrophic postmenopausal state. Thus, tibolone is suggested for those postmenopausal women who have concerns about HRT.