the effect of intrauterine human chorionic gonadotropin injection before embryo transfer on the implantation and pregnancy rate in infertile patients: a randomized clinical trial

background: implantation is one of the essential steps for the success of assisted reproductive techniques (art). their success depends on three main factors: embryo quality, endometrial receptivity (er), and synchrony between embryo and endometrium. there are various factors that regulate the complex process of implantation. in this regard, one may refer to human chorionic gonadotropin (hcg) as the most important factor.objective: this study aims to investigate the effect of intrauterine hcg injection before embryo transfer (et) on pregnancy outcome in infertile couples.materials and methods: a total of 159 patients undergone in vitro fertilization/ intracytoplasmic sperm injection (ivf/icsi) with an antagonist protocol were evaluated. patients were divided into three groups (n=53). group 1 received 500 iu of hcg, group 2 received 1000 iu of hcg intrauterine injection before et, and the control group underwent et without hcg preceding intrauterine injection.results: there was no significant difference among the groups. the implantation rates were 18.86%, 13.52%, and 14.37%, chemical pregnancy rates were 34%, 32.1%, and 35.3%, and clinical pregnancy rates were 34%, 32.1%, and 31.4% respectively.conclusion: the pregnancy outcome in ivf/icsi /et cycles cannot be improved through hcg intrauterine injections before et.