Effect of adding human chorionic gonadotropin to frozen thawed embryo transfer cycles with history of thin endometrium

Background: Embryo implantation process is a complex phenomenon and depends on fetal and maternal factors interaction. Endometrial thickness is needed for successful implantation. Objective: We designed this study in order to assess adding human chorionic gonadotropin (HCG) to the conventional protocol in endometrial preparation in women with thin endometrium and a history of in vitro fertilization–embryo transfer (IVF-ET) failure. Materials and Methods: The non-randomized clinical trial study (quasi experimental design) was performed on 28 patients. Participants were women who were candidate for frozen-thawed (ET) and had two previous failed ET cycles because of thin endometrial. HCG was administrated (150 IU, intramuscular) from the 8th day of cycle and when endometrial thickness reached at least 7mm HCG was discontinued and frozen thawed ET was done. Results: Totally 28 patients were included. The mean ± SD age of participants was 30.39±4.7. The mean of endometrium thickness before and after HCG were 5.07±0.43 and 7.85±0.52, respectively p<0.001. Also, there were five clinically and chemically pregnant women. Conclusion: The findings of the study suggested that adding HCG to the conventional preparation method was an effective protocol and significantly improved endometrial thickness and pregnancy outcomes in women with previous embryo transfer failure because of thin endometrium.