Clinical outcomes comparison of single fresh and frozen-thawed superior blastocyst transfer

Objectives: To compare the clinical outcomes of single fresh and frozen-thawed superior blastocyst transfer in patients for the first transfer. Methods: This study included 770 single fresh blastocyst and 639 single frozenthawed blastocyst transfers from January 2013 to January 2016. All the fresh and frozen-thawed embryo transfer was first transfer for the patients. The patients were divided into fresh group and frozen-thawed group. Main outcome measure: female age, endometrial thickness, infertility duration, clinical pregnancy, ectopic pregnancy and abortion rate. Results: We observed that there was no significant difference in female age, endometrial thickness, and infertility duration and abortion rate between two groups. It’s worth noting that the clinical pregnancy rate in fresh group was lower than frozen-thawed group (66.36% vs 68.39%, P = 0.420) and the ectopic pregnancy rate was higher in fresh group than frozen-thawed group (1.57% vs 0.46%, P = 0.096). Conclusions: The data support the view that the frozen-thawed transfer may be a better clinical strategy for patients with superior blastocyst in their first transfers.