A randomised controlled trial comparing GnRH antagonist Cetrorelix with GnRH agonist Leuprorelin for endometrial thinning prior to transcervical resection of

Objectives To compare the effectiveness of leuprorelin and cetrorelix, when used as preoperative endometrial thinning agents prior to transcervical resection of endometrium (TCRE). Design A prospective, double-blind randomised controlled trial. Setting Gynaecological department of a UK district general hospital. Participants A total of 106 premenopausal women with dysfunctional uterine bleeding, undergoing TCRE. Interventions Women were equally randomised to 3.75 mg of leuprorelin acetate (3-4 weeks) or 3 mg cetrorelix (4-7 days) prior to TCRE. About 1 ml saline was given as placebo in both arms. Main outcome measures Amenorrhoea rate at 6 months, endometrial thickness using transvaginal ultrasound on the day of operation. Results A total of 100 women completed the trial with no loss to follow up. Amenorrhoea rate at 6 months after surgery was high in both groups (80% cetrorelix and 84% leuprorelin) with no statistical significance. All endometrial outcome measures including endometrial thickness on ultrasound, histology and operative appearance were more favourable in leuprorelin group as compared with cetrorelix (P values 0.013, < 0.001 and 0.003 respectively). More women in leuprorelin group had hot flushes as compared with cetrorelix (15/50 versus 6/50; P = 0.047). No significant differences were seen in other outcome measures. Conclusions In dosages used, leuprorelin produced more consistent thinning of the endometrium as compared with cetrorelix, although this did not make any significant difference to operative or menstrual outcomes. The endometrial thinning effect with cetrorelix does appear to be more favourable than that seen at postmenstrual phase in other studies. The optimum (possibly higher) dosage of cetrorelix for this purpose has not yet been established.