Analysis on related factors of survival of frozen-thawed embryos

Objective: To explore the effects of age,fertilization types,methods of embryos cryopreservation,and embryo frozen storage time on survival of frozen- thawed embryos. Methods: A total of 1 255 cycles of frozen- thawed embryo transfer were retrospectively analyzed,then they were divided into different groups according to age,fertilization types,methods of embryos cryopreservation,and embryo frozen storage time. The embryo survival rates,embryo complete survival rates,and clinical pregnancy rates in different groups were compared. Results: The embryo survival rate,embryo complete survival rate,and clinical pregnancy rate in vitrification cryopreservation group were 93. 4%,95. 9%,and 48. 8%,respectively; the embryo survival rate,embryo complete survival rate,and clinical pregnancy rate in programmed freezing group were 81. 2%,54. 9%,and 30. 1%,respectively,there were statistically significant differences between the two groups( P 0. 05). Age,fertilization types,and embryo frozen storage time had no significant impact on embryo survival rate and embryo complete survival rate( P 0. 05). Conclusion: Compared with programmed freezing,vitrification cryopreservation can achieve higher embryo survival rate,embryo complete survival rate,and clinical pregnancy rate; the impact of embryo frozen storage time on survival of frozen- thawed embryos within three years can be ignored.