玻璃化冷冻法在未成熟卵子冷冻技术中的应用

Investigation on the different protocols for vitrification of human immature oocytes

目的:探讨玻璃化冷冻法在未成熟卵子冷冻方面的应用价值。方法:选取GV期卵母细胞744枚,随机分为5组,A组(128枚),GV期卵子直接进行未成熟卵母细胞体外培养(IVM);B组(220枚),GV期卵子直接行玻璃化冷冻;C组(155枚),GV期卵子直接行IVM,待培养至MⅡ期,再行玻璃化冷冻;D组(112枚),GV期卵子去除冠-丘细胞,行玻璃化冷冻;E组(129枚),GV期卵子保留除冠-丘细胞行玻璃化冷冻。比较各组卵母细胞的存活率、成熟率、受精率、卵裂率及囊胚形成率。结果:与A组相比,B组和C组的成熟率、受精率、卵裂率和囊胚形成率均降低(P<0.05);B组与C组间存活率、成熟率、受精率、卵裂率和囊胚形成率无差异(P>0.05)。E组的成熟卵子率较D组提高(P<0.05),但两组在解冻卵子存活率、受精率、2细胞数和>2细胞数方面无差异(P>0.05)。结论:未成熟卵子的玻璃化冷冻保留冠-丘细胞可显著提高冻融效果。

Objective ： To study the outcomes of different vitrification protocols for the cryopreservation of human immature oo-cytes. Methods ： A total of 744 spared oocytes in GV stage were collected and randomly allocated into 5 groups. Group A （ n = 128 ） ： directly for in vitro maturation （IVM） ; Group B （ n = 220） ： vitrified without IVM ; Group C （ n = 155 ） ： IVM to M Ⅱ stage and then vitrified; Group D （n = 112） ： vitrified after crown- cumulus cells removed; Group E （n = 129） ： vitrified with presence of crown - cumulus ceils. The rates of survival, maturation, fertilization, cleavage and blastocyst formation of the frozen - thawed/fresh GV oocytes were compared between the groups. Resuhs ： Compared with those in Group A, the rates of maturation, fertility, cleavage and blastocyst formation in Group B or Group C were significantly lower （ P 〈 0.05 ）. There was no significant difference between Group B and Group C in survival, maturation, fertilization, cleavage, blastocyst forma- tion rate （ P 〉 O. 05 ）. The rate of maturation in Group E was higher than that of Group D （ P 〈 0.05 ）, but there was no sig-nificant difference between these two groups in survival rate, fertilization rate, number of 2 - cell embryos or 〉 2 - cell em- bryos （P 〉 0. 05 ）. Conclusion： Vitrification of human immature oocytes with intact crown - cumulus cells can significantly im- prove the cryopreservation outcomes.