Investigating abnormal bleeding on HRT or tamoxifen: the role of ultrasonography.

In western countries hormone replacement therapy (HRT) is a widely used therapeutic and/or preventive medication in post-menopausal women. Its impact on the endometrium has been extensively investigated. The critical issue is whether and how to monitor the endometrium in women who are taking HRT. Transvaginal ultrasound is a potential candidate for this role. Evidence for the efficiency of transvaginal sonography (TVS) in this context is limited. The criteria used to define a normal or abnormal result in women taking HRT are based largely on data from post-menopausal women who are not taking this treatment. This extrapolation is probably reasonable as long as some degree of caution is used. The use of normative data from post-menopausal women for those taking selective oestrogen receptor modulators (SORMs) is not advised and should be utilized only in the context of research studies as insufficient data exist on which to base cut-off values to discriminate between normal and abnormal endometria.