Medical dilatation of the non-pregnant cervix: the effect of ethinyl oestradiol on the visibility of the transformation zone.

The cervical transformation zone (TZ) was not fully visible in 25 women referred to the colposcopy clinic with cytological suspicion of cervical intraepithelial neoplasia (CIN). Each was given a 5-day course of oral ethinyl oestradiol during the follicular phase of the menstrual cycle, and colposcopy was then repeated. The transformation zone was visible at this second examination in 16 of the 25 patients. Of these patients, 11 were treated with a local destructive technique, nine by laser, two by cryocautery; one patient had a cone biopsy, and four patients did not require treatment. Although cone biopsy was necessary in 8 of the remaining 9 patients it is encouraging that the use of a simple medical regimen allowed us to avoid conisation and its morbidity in almost two thirds of these patients.