RESUMO
Objective:To investigate the effect of repeated freezing and thawing on the clinical outcome of embryo transfer.Methods:A total of 48 cycles of twice frozen-thawed embryo (blastocyst) transfer in the reproductive medicine department, Shenzhen Luohu People′s Hospital from 2015 to 2020 were collected as the observation group, and 98 cycles of one frozen-thawed blastocyst transfer in the same period were randomly selected as the control group. The patient′s age, endometrial thickness, average number of transferred embryos, average number of high-quality embryos transferred, embryo recovery rate, implantation rate, clinical pregnancy rate, abortion rate, ectopic pregnancy rate, and live birth rate were compared.Results:There was no significant difference in age, endometrial thickness, number of embryos transferred and high-quality embryos transferred between the two groups (all P>0.05). There was no significant difference in embryo recovery rate, ectopic pregnancy rate, abortion rate and live birth rate between the two groups (all P>0.05). The embryo implantation rate and clinical pregnancy rate in the observation group were significantly lower than those in the control group (32.47% vs 55.70%, 39.58% vs 66.33%, all P<0.05). Conclusions:The clinical pregnancy rate was significantly lower than that of the control group after repeated vitrification of frozen-thawed embryo transfer, which may affect the subsequent developmental potential of embryos.