REVIEW OF THE ENDOMETRIAL SAFETY DURING INTRAVAGINAL TREATMENT WITH ESTRIOL

To gain more insight into whether intravaginal treatment of local urog enital complaints with the mild acting oestrogen estriol is capable of inducing proliferaton of the endometrium, the results of the clinical studies that have been published over the years have been pooled. Of a total of 19 studies that initially had been selected, four were excl uded from the analysis because no baseline biopsies were available, tw o because endometriae had been evaluated using methods other than with histology, and one study because a sustained-release preparation was used. Pooling of 12 studies (214 subjects) revealed a reasonable amoun t of long-term data on intravaginal estriol treatment with 61 evaluabl e biopsies after 6 months and 58 after 12 months. In addition, 13 biop sies were available after 2 years. It appeared that intravaginal estri ol treatment using the recommended dosages did not result in endometri al proliferation. All 337 post-baseline biopsies that have been report ed in the literature were classified as atrophic. It can be concluded that single daily treatment with intravaginal estriol in the recommend ed doses in postmenopausal women is safe and without an increased risk of endometrial proliferation or hyperplasia. Consequently, there is n o need to add sequential progestogens with these preparations and no w ithdrawal bleedings will be induced.