Intervention type: drug~Intervention name: letrozole then misoprostol~Description :letrozole 2.5mg twice per day for 2days then misoprostol 800mcg for all patients to induce abortion~Arm group label:study group~Intervention type :drug~Intervention name:placebo then misoprostol~Description : placebo for 2days then 800mcg misoprostol to all patients to induce abortion~Arm group label: control group
this study will compare the efficacy of using letrozole pre treatment before misoprostol versus using misoprostol only in the induction of first trimester missed abortion.