Transvaginal sonography of the endometrium in postmenopausal women: monitoring the effect of hormone replacement therapy.

BACKGROUND: It is well known that progestins given in sufficient dosage reduce the risk of endometrial cancer and endometrial hyperplasia. It is also not uncommon that patients receiving hormone replacement therapy (HRT) require endometrial biopsy in order to evaluate the effects of oestrogens and progestogens on endometrium. However, endometrial biopsy is often associated with pain and discomfort, and transvaginal sonography has been suggested as a new and painless method of monitoring the effects of HRT on the endometrium.

METHODS: Transvaginal ultrasonography was performed in a series of women on several regimens of HRT immediately prior to endometrial biopsy (Cornier cannula). We correlated the morphology and thickness of the endometrium as assessed by transvaginal ultrasonography with the endometrial histology. Patients were assigned into four groups. The first (n = 15) received 0.6 mg/day of conjugated equine oestrogen (CEE) cyclically and the second (n = 6) received 50 micrograms/day of transdermal oestradiol cyclically. All these groups also received 5 mg of medroxy-progesterone acetate (MPA) sequentially for the last 12 days of HRT, while the third therapy group (n = 7) received 0.625 mg/day of CEE and 5 mg/day of MPA uninterruptedly. The fourth group (n = 8) constituted a treatment-free control group. In total 36 biopsies were taken. Our initial results suggest that endometrial thickness under 4 mm measured by ultrasonography is not associated with endometrial abnormalities and that transvaginal ultrasonographic scanning of the endometrium may be a useful tool in determining which patients require endometrial histologic evaluation and perhaps in detecting those who need adjustment in the progestin dosage.