Objective: To investigate the effect of human chorionic gonadotropin(HCG) intrauterine perfusion on pregnancy outcome in patients undergoing repeated implantation failure(RIF) during freeze-thawed embryo transfer (FET). Methods: Retrospective analysis was based on the data of 218 FET cycles with RIF patients from our institution from January 2017 to June 2018. According to the presence or absence of intrauterine perfusion before transplantation, 80 cases were assigned into observation group(group G1) and 138 cases control group(group G2). Patients' general situations, cycle conditions and pregnancy outcomes were compared between these two groups. A further comparison of the clinical outcome of HCG intrauterine perfusion of different types of embryos(cleavage stage embryo or blastocyst) was made. Results: In group G1,the clinical pregnancy rate(53.750%), embryo implantation rate(31.677%) and live birth rate(41.250%) were all higher than those in the group G2 respectively(34.783%, 21.456%, 23.913%), the differences were statistically significant(P<0.05). In RIF patients who underwent blastocyst transfer, their clinical pregnancy rate(60.00% vs 37.5%) and embryo implantation rate(44.068% vs 25.000%) were superior to the control group, with a statistical difference(P<0.05), however, early abortion rate(14.286% vs 29.630%), ectopic pregnancy rate(0 vs 3.704%), multiple pregnancy rate(23.810% vs 11.111%) and live birth rate(42.857% vs 25.000%) were not statistically significant(P>0.05). Conclusion: For patients with RIF who are planning FET, HCG intrauterine perfusion before transplantation is beneficial to embryo implantation and clinical pregnancy rate, which has certain positive significance for improving the pregnancy outcome of RIF patients. This research also shows that HCG intrauterine perfusion may be more suitable for patients undergoing blastocyst transfer than cleavage stage embryo transfer.
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