Reproductive Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Department of Gynecology and Obstetrics, Jing Men NO.2 People's Hospital, Jingmen, China.
Reprod Biomed Online. 2021 Jan;42(1):75-82. doi: 10.1016/j.rbmo.2020.11.007. Epub 2020 Nov 20.
Does repeated cryopreservation process affect embryo implantation potential and neonatal outcomes of human embryos?
This retrospective cohort study was conducted in the Reproductive Medicine Centre, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. All assisted reproductive technology (ART) cycles were carried out between January 2014 and December 2018. Preferentially matched participants were divided into three groups according to the times of embryo cryopreservation: the fresh group (n = 249), the cryopreservation group (n = 244) and the re-cryopreservation group (n = 216). Embryo implantation rate, live birth rate, miscarriage rate and neonatal complication rate were compared among these three groups.
The embryo implantation rate, clinical pregnancy rate and live birth rate in the re-cryopreservation group were significantly lower, and the miscarriage rate also slightly increased. Logistic regression analysis indicated that embryos with repeated cryopreservation and lower trophectoderm scores were at higher risk of embryo implantation failure in single embryo transfer cycles (OR 1.79 and 1.56, respectively). No significant differences were observed in gender, gestational age, birthweight, neonatal abnormality and neonatal complications among the groups.
Our findings demonstrate the adverse effect of repeated cryopreservation on embryo implantation potential. The study offers embryologists and reproductive clinicians a warning of detrimental role of repeated cryopreservation. If unnecessary, it is strongly recommended to avoid repeated practice of vitrification and warming on embryos.
反复的冷冻保存过程是否会影响人类胚胎的胚胎着床潜能和新生儿结局？
本回顾性队列研究在华中科技大学同济医学院附属同济医院生殖医学中心进行。所有辅助生殖技术（ART）周期均在 2014 年 1 月至 2018 年 12 月之间进行。根据胚胎冷冻保存的次数，优先匹配参与者被分为三组：新鲜组（n=249）、冷冻组（n=244）和再冷冻组（n=216）。比较三组的胚胎着床率、活产率、流产率和新生儿并发症发生率。
再冷冻组的胚胎着床率、临床妊娠率和活产率显著降低，流产率也略有增加。Logistic 回归分析表明，在单胚胎移植周期中，反复冷冻保存和滋养外胚层评分较低的胚胎着床失败的风险更高（OR 分别为 1.79 和 1.56）。各组之间的性别、胎龄、出生体重、新生儿异常和新生儿并发症无显著差异。
我们的研究结果表明，反复冷冻保存对胚胎着床潜能有不良影响。该研究为胚胎学家和生殖临床医生敲响了警钟，提示反复冷冻保存可能带来有害作用。如果没有必要，强烈建议避免对胚胎进行反复的玻璃化和融冻操作。
