Endometrial Safety During Hormone Replacement Therapy

This study compared transvaginal ultrasonography with histologic findings in endometrial evaluation of postmenopausal women using hormone replacement therapy and evaluated the endometrial safety of three different hormone replacement therapy regimens. Eighty-four postmenopausal women underwent transvaginal ultrasonography immediately before endometrial biopsy and after 6 months. Endometrial safety was evaluated using (a) no therapy, (b) a vaginal ring, (c) tibolone, and (d) transdermal 17β-estradiol. Climacteric symptoms, bleeding pattern, and endometrial histologic features were studied. Endometrial evaluation was conveniently performed by transvaginal ultrasonography, and endometrial thickness correlated well with biopsy findings. All treatment regimens effectively relieved climacteric symptoms. Endometrial proliferation was not observed. If endometrial thickness was <5 mm, the endometrial biopsy sample was classified as either inactive/atrophic or insufficient for histopathologic diagnosis. All three hormone replacement therapies were safe with respect to the endometrium. Using 5 mm endometrial thickness as the cutoff point, more than 90% of biopsies could be avoided. The three regimens were effective in alleviating menopausal symptoms.