Pre-operative endometrial thinning agents before endometrial destruction for heavy menstrual bleeding.

Heavy menstrual bleeding is one of the most common reasons for referral of premenopausal women to a gynaecologist. Although medical therapy is generally first line, many women eventually will require further treatment. Endometrial ablation by hysteroscopic and more recent "second-generation" devices such as balloon, radiofrequency or microwave ablation offers a day-case surgical alternative to hysterectomy. Complete endometrial destruction is one of the main determinants of treatment success. Surgery is most effective if undertaken when endometrial thickness is less than four millimeters. One option is to perform the surgery in the immediate postmenstrual phase, which is not always practical. The other option is to use hormonal agents that induce endometrial thinning pre-operatively. The most commonly evaluated agents are goserelin (a gonadotrophin-releasing hormone analogue, or GnRHa) and danazol. Other GnRH analogues and progestogens have also been studied, although fewer data are available. It has been suggested that these agents will reduce operating time, improve the intrauterine operating environment and reduce absorption of fluid used for intraoperative uterine cavity distension. They may also improve long-term outcomes, including menstrual loss and dysmenorrhoea.