蔗糖浓度及ICSI前培养时间对人卵母细胞慢速冷冻影响的初步研究

Effect of Sucrose Concentrations and Different Incubation Time before ICSI on Oocyte Cryopreservation by a Slow-freezing Protocol

目的:研究2种蔗糖浓度对人类卵母细胞冻融结果的影响。方法:采用慢冻-快融程序化冷冻方法冻融不同时期的人卵母细胞,根据冷冻液中蔗糖浓度不同分为二组(A组:0.2mol/L蔗糖组;B组:0.3mol/L蔗糖组),比较其复苏后存活情况。B组复苏后成熟卵母细胞培养不同的时间行单精子卵胞浆内注射(ICSI),分析培养时间对卵母细胞受精和发育结果的影响。结果:相对于A组的冷冻方法,B组明显提高了未成熟卵母细胞和成熟卵母细胞的存活率(72.0% vs 54.4%,68.8% vs 44.4%),二组卵母细胞复苏后形态异常率无明显差异;复苏后存活的成熟卵母细胞ICSI前培养3-4h后受精率、优质胚胎率、囊胚形成率明显高于培养1h、2h和5h。结论:适当提高蔗糖浓度更有利于各时期卵母细胞的冻存,复苏的成熟卵母细胞培养3-4h有助于卵母细胞结构的恢复,提高正常受精率和后期发育潜能。

Objective： To study the effect of two sucrose concentrations on oocyte cryopreservation. Methods： Different sucrose concentrations （group A： 0.2 mol/L, group B： 0.3 mol/L） were used to study the survival rate of the frozen-thawed human oocytes. After thawing, ICSI was performed to mature oocyte of group B after culturing in different time, and the effect of culture time on oocyte fertilization and development. Results： A statistically increase was observed in the survival rate in group B compared with that in group A. Oocyte fertility rates and development rates were significant improved when cultured 3 h and 4 h compared with those when cultured 1 h, 2 h and 5 h （P〈0.05）. The cleavage rate were similar among all groups. Conclusion： The increased sucrose concentration achieved good survival using a slow-freezing and rapid-thawing protocol. The 3-4 h postthaw incubation could permit restoration of the meiotic spindles, thus facilitating normal fertilization and developmental potential.