A prospective, randomised, cross-over study comparing the effects of clomiphene citrate and cyclofenil on endometrial morphology in the luteal phase of normal, fertile women.

OBJECTIVE: To examine the effect of two anti-oestrogens, clomiphene citrate and cyclofenil, on endometrial morphology in the luteal phase. DESIGN: A prospective, randomised, cross-over study. SETTING: Jessop Hospital for Women, Sheffield, UK. SUBJECTS: 10 women who were previously fertile and regularly cycling. INTERVENTION: The administration of clomiphene citrate or cyclofenil in the treatment cycles. A LH timed endometrial biopsy was taken on day LH + 6. MAIN OUTCOME MEASURES: Histological dating and morphometric analysis of the endometrial sample. RESULTS: Only one out of 10 subjects had abnormal endometrium. There was no difference in the results between cycles treated with clomiphene citrate and cyclofenil. CONCLUSIONS: Clomiphene citrate or cyclofenil does not have a major adverse effect on endometrial morphology in the luteal phase of normal fertile subjects. The possible adverse effects of anti-oestrogens on endometrium may have been previously overestimated.