Centre of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University, Third Hospital, Beijing 100191, China; Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing 100191, China.
Centre of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University, Third Hospital, Beijing 100191, China; Key Laboratory of Assisted Reproduction, Ministry of Education, Beijing 100191, China.
Reprod Biomed Online. 2017 Dec;35(6):627-632. doi: 10.1016/j.rbmo.2017.08.016. Epub 2017 Aug 24.
Repeated cryopreservation of surplus embryos from frozen-thawed cycles should occasionally be considered. The purpose of this retrospective cohort study was to evaluate the pregnancy and perinatal outcome of repeated cryopreservation by vitrification of human blastocysts derived from slowly frozen-thawed day 3 embryos. In total, 571 vitrified-warmed blastocyst transfer cycles were investigated. The vitrified-warmed blastocysts were derived from slowly frozen-thawed cleavage embryos (twice-cryopreserved group) or fresh embryos (control group) cultured to the blastocyst stage. Age, body mass index, endometrial thickness, blastocyst developmental rate and number of embryos transferred were not significantly different between twice-cryopreserved and control groups. Clinical pregnancy and implantation rates were also similar. Compared with controls, the miscarriage rate was significantly higher in the twice-cryopreserved group (33.93% versus 19.07%, P = 0.017). This resulted in a significantly lower live birth rate in the twice-cryopreserved group than in controls (29.13% versus 39.18, P = 0.038). No differences were observed in mean gestational age, birthweight and sex ratio of newborns between groups. In conclusion, acceptable clinical pregnancy outcomes may be expected from transfer of twice-cryopreserved human embryos. While the neonatal outcome is not affected, the correlation between the risk of higher pregnancy loss and repeated cryopreservation needs further investigation.
反复冷冻保存从冷冻-解冻周期中剩余的胚胎偶尔应该被考虑。本回顾性队列研究的目的是评估通过玻璃化法冷冻解冻的第 3 天缓慢冷冻胚胎衍生的人类囊胚的重复冷冻保存的妊娠和围产结局。共研究了 571 个玻璃化解冻囊胚移植周期。玻璃化解冻的囊胚来源于缓慢冷冻解冻的卵裂期胚胎（两次冷冻保存组）或新鲜胚胎（对照组）培养至囊胚阶段。两次冷冻保存组和对照组之间年龄、体重指数、子宫内膜厚度、囊胚发育率和胚胎移植数量无显著差异。临床妊娠率和种植率也相似。与对照组相比，两次冷冻保存组的流产率显著升高（33.93%对 19.07%，P=0.017）。这导致两次冷冻保存组的活产率明显低于对照组（29.13%对 39.18%，P=0.038）。两组新生儿的平均胎龄、出生体重和性别比无差异。总之，从两次冷冻保存的胚胎移植中可能获得可接受的临床妊娠结局。虽然新生儿结局不受影响，但妊娠丢失风险与反复冷冻保存之间的相关性需要进一步研究。
