To compare the effect of endometrial preparation using natural cycle versus hormone replacement cycle on frozen embryo transfer outcomes in ovulatory infertile women : A randomised controlled trial

This study is a randomized controlled trial comparing the effectiveness and safety of natural cycle frozen embryo transfer  versus hormone replacement cycle FET  in ovulatory infertile women Conducted at the ART Centre,Department of Obstetrics & Gynecology AIIMS New Delhi from ethical clearance to July 2026 the study will include 60 women aged 21 to 40 years with regular menstrual cycles undergoing day 5 blastocyst transfer Exclusion criteria include anovulation  systemic diseases PCOS and uterine abnormalities Participants will be randomized into two groups NC-FET where ovulation is monitored through serial transvaginal ultrasound and hormonal assessment before progesterone supplementation and embryo transfer and HRC FET where estradiol valerate is used for endometrial preparationfollowed by progesterone supplementation and embryo transfer The primary objective is to compare clinical pregnancy rates while secondary outcomes include ongoing pregnancy rate early miscarriage rate ectopic pregnancy rate  and cycle cancellation rate Statistical analysis will use descriptive and inferential tests with significance set at p less than 0.05 This study aims to provide robust evidence to guide the selection of the optimal FET protocol in ovulatory infertile women