[Intrauterine injection of human chorionic gonadotropin improves pregnancy outcome in patients with repeated implantation failure in frozen-thawed embryo transfer]

To investigate whether intrauterine injection of human chorionic gonadotropin (hCG) before the embryo transfer in a frozen-thawed transfer cycle can improve the pregnancy outcome in the patients with repeated implantation failure (RIF).
 Methods: Prospective randomized-controlled trial was adopted. A total of 140 patients, who underwent thawed embryo transplantation and were in line with the diagnosis of RIF, were included. Other patients with some factors, such as uterine malformation, postoperative uterine cavity sticking, tubal effusion, endocrine diseases and endometriosis, were excluded. The patients were randomly divided into 2 groups through the computer random number table: an hCG intrauterine perfusion group and a control group. There was no significant difference in the age, the estradiol level, the number of transplanted embryos, the number of optimal embryos, and the thickness of the endometrium before transplantation between the 2 group (all P>0.05). The hCG+G2 fluid and the G2 fluid were prepared on the day of embryo transfer, and 40 μL of which was injected at an intrauterine site at 3 minutes before embryo transfer in the hCG intrauterine perfusion group and the control group, respectively. The clinical pregnancy rate and implantation rate in the 2 groups were compared.
 Results: The implantation rate and the clinical pregnancy rate in the hCG intrauterine perfusion group were higher than those in the control group (both P<0.05).
 Conclusion: The intrauterine injection of hCG can improve the implantation rate and pregnancy rate in cryopreserved embryo transfer in patients with RIF.