Hong Yeon Hee, Jee Byung Chul
Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea.
Clin Exp Reprod Med. 2024 Mar;51(1):57-62. doi: 10.5653/cerm.2023.06499. Epub 2024 Feb 29.
The purpose of this study was to use a mouse model to investigate the blastocyst formation rate in vitrified-warmed embryos derived from vitrified-warmed oocytes.
Metaphase II oocytes obtained from BDF1 mice were vitrified and warmed, followed by fertilization with epididymal sperm. On day 3, a total of 176 embryos, at either the eight-cell or the morula stage, were vitrified-warmed (representing group 1). For group 2, 155 embryos at the same developmental stages were not vitrified, but rather were directly cultured until day 5. Finally, group 3 included day-5 blastocysts derived from fresh oocytes, which served as fresh controls. The primary outcome measured was the rate of blastocyst formation per day-3 embryo at the eight-cell or morula stage.
The rates of blastocyst formation per day-3 embryo were comparable between groups 1 and 2, at 64.5% and 69.7%, respectively (p>0.05). The formation rates of good-quality blastocysts (expanded, hatching, or hatched) were also similar for groups 1 and 2, at 35.5% and 43.2%, respectively (p>0.05). For the fresh oocytes (group 3), the blastocyst formation rate was 75.5%, which was similar to groups 1 and 2. However, the rate of good-quality blastocyst formation in group 3 was 57.3%, significantly exceeding those of group 1 (p=0.001) and group 2 (p=0.023).
Regarding developmental potential to the blastocyst stage, vitrified-warmed day-3 embryos originating from vitrified-warmed oocytes demonstrated comparable results to non-vitrified embryos from similar oocytes. These findings indicate that day-3 embryos derived from vitrified-warmed oocytes can be effectively cryopreserved without incurring cellular damage.
本研究旨在使用小鼠模型研究由玻璃化冷冻-解冻卵母细胞产生的玻璃化冷冻-解冻胚胎的囊胚形成率。
从BDF1小鼠获得的中期II卵母细胞进行玻璃化冷冻和解冻，然后用附睾精子受精。在第3天，总共176个处于八细胞或桑葚胚阶段的胚胎被玻璃化冷冻-解冻（代表第1组）。对于第2组，155个处于相同发育阶段的胚胎未进行玻璃化冷冻，而是直接培养至第5天。最后，第3组包括来自新鲜卵母细胞的第5天囊胚，作为新鲜对照。测量的主要结果是八细胞或桑葚胚阶段的每个第3天胚胎的囊胚形成率。
第1组和第2组之间，每个第3天胚胎的囊胚形成率相当，分别为64.5%和69.7%（p>0.05）。第1组和第2组的优质囊胚（扩张、孵化或已孵化）形成率也相似，分别为35.5%和43.2%（p>0.05）。对于新鲜卵母细胞（第3组），囊胚形成率为75.5%，与第1组和第2组相似。然而，第3组的优质囊胚形成率为57.3%，显著超过第1组（p=0.001）和第2组（p=0.023）。
关于发育至囊胚阶段的潜力，由玻璃化冷冻-解冻卵母细胞产生的玻璃化冷冻-解冻第3天胚胎与来自相似卵母细胞的未玻璃化冷冻胚胎表现出相当的结果。这些发现表明，由玻璃化冷冻-解冻卵母细胞产生的第3天胚胎可以有效地进行冷冻保存而不会造成细胞损伤。
