Monitoring of oestrogen replacement therapy by vaginosonography of the endometrium.
To prevent hyperplasia and carcinoma of the endometrium during oestrogen replacement therapy (ORT), the addition of progestogens once a month is considered mandatory. However, there is no sound scientific basis for this assumption. As the addition of progestogens has several disadvantages, it is important to minimize the frequency of progestogen addition. Vaginosonography is a rather new technique which has not yet been used for monitoring ORT. In this study the increase in endometrial thickness, as measured by vaginosonography, was taken as an indicator of stimulation of the endometrium by oestrogens. Oestrogen treatment was started in post-menopausal women with little endometrium (thickness less than 3 mm). As long as there was virtually no increase during oestrogen treatment, no progestogen was added, but where considerable growth occurred (greater than 3 mm) progestogen was administered. By means of vaginosonography the growth of the endometrium can be monitored precisely on an individual basis. It is thus possible to distinguish women with a slow growing endometrium from those with an endometrium that grows fast. In this way it will perhaps become possible to minimize progestogen addition during ERT by tailoring dosage to individual requirements.