Abnormal uterine bleeding on hormone replacement: the importance of intrauterine structural abnormalities

To examine the importance of submucous myomas and endometrial polyps before and after menopause and in abnormal withdrawal bleeding on hormone replacement therapy (HRT).

Between May 1991 and May 1993, women presenting with abnormal withdrawal bleeding on HRT (n = 106), menstrual problems in pre-menopause (n = 92), or postmenopausal bleeding (n = 33) underwent diagnostic outpatient hysteroscopy for the presence of intrauterine structural abnormalities. The findings were compared with a control group of post- and perimenopausal women without bleeding problems (n = 183).

When compared with women who had normal uterine cavities, the presence of submucous myomas was associated with a threefold increase in the risk of abnormal menstrual bleeding in premenopausal women (odds ratio [OR] 3.34, 95% confidence interval [CI] 1.77-6.43; P < .001) and a twofold increase in the risk of abnormal withdrawal bleeding in post- and perimenopausal women (OR 2.4, 95% CI 1.25-4.53; P = .004). This did not seem to be related to the number of myomas detected. The frequency of endometrial polyps was not found to be significantly higher in women who had menstrual disorders or abnormal withdrawal bleeding on HRT. Postmenopausal bleeding without hormonal stimulation was not significantly associated with submucous myomas or polyps.

As increasingly more women request HRT, bleeding problems presenting pre-menopause can no longer be expected to resolve "naturally" after menopause. In the presence of submucous myomas, these women will continue to have a higher risk of abnormal withdrawal bleeding when treated with hormone replacement, whereas endometrial polyps are not associated with an increased bleeding risk. Hysteroscopic assessment of the uterine cavity and subsequent counseling as to the risk of heavy or prolonged bleeding will be helpful in their future management and may improve compliance.