The need for endometrial preparation before endometrial ablation has been challenged in a systematic review of randomised controlled trials. The only benefit for endometrial preparation was better operating conditions for the surgeon.
With first-generation techniques, endometrial preparation with GnRH analogues reduces operating times and fluid absorption but increases cervical resistance, therefore making dilatation more difficult.
With second generation techniques, endometrial preparation did not offer any advantage, but was associated with a higher incidence of adverse effects.