Effect of intrauterine administration of human chorionic gonadotropin one day before fresh blastocyst transfer on clinical outcomes: a quasi-experimental study.

Introduction: embryo implantation is a crucial step for assisted reproductive technology (ART) achievement. Human chorionic gonadotropin (hCG) is one of the main regulators of the implantation process. Studies focusing on the impact of intrauterine hCG infusion at the time of embryo transfer on clinical ART outcomes have shown controversial results, mainly at blastocyst stage. In this study, we aimed to investigate whether intrauterine hCG infusion one day before human blastocyst transfer in fresh invitro fertilization (IVF) cycles enhances implantation and pregnancy rates.

Methods: a total of 174 subfertile women undergoing autologous fresh blastocyst transfer were enrolled in this randomized prospective study. Patients were randomly divided into three groups; group 1 (n = 54) and group 2 (n = 59) received an intrauterine injection of respectively 500 IU and 1000 IU of hCG one day before blastocyst transfer and the control group (n= 61) did not receive any intrauterine injection. The pregnancy and implantation rates were compared between the three study groups.

Results: significant difference was found between the study groups. The bio chemical pregnancy rates were 25.9%, 30.5% and 29.5%, the clinical pregnancy rates were 24.1%, 27.1% and 27.9% and the implantation rates were 14.9%, 17.9% and 18.7% respectively in group 1,2 and control group.

Conclusion: our results have shown that clinical outcomes in fresh IVF cycles cannot be improved through intrauterine hCG administration one day prior to blastocyst transfer, neither with 500 IU of hCG nor with a higher dose of 1000 IU of hCG.