人类不同时期未成熟卵母细胞玻璃化冷冻后发育潜能的比较

Study on Developmental Potential of Human Immature Oocytes at Different Developmental Stages after Vitrification

目的:探索未成熟卵子的最佳冷冻时期。方法:收集卵胞质内单精子显微注射-胚胎移植(ICSI-ET)周期中未成熟的卵母细胞,按其成熟度分为生发泡期(GV组)卵子179枚和第一次减数分裂中期(MI组)卵子323枚,所有卵子均经玻璃化冷冻,解冻后行体外成熟(IVM)培养,ICSI受精,观察比较GV组和MI组解冻后存活、体外成熟、受精及胚胎发育情况。结果:GV组复苏存活率显著高于MI组(83.24%vs 75.54%,P=0.045),MI组体外成熟率、受精率、卵裂率、优质胚胎率均略均高于GV组,但无统计学差异(P>0.05),MI组可利用胚胎率显著高于GV组(78.67%vs 60.53%,P=0.041)。结论:超促排卵周期中未成熟卵母细胞先玻璃化冷冻保存,再行体外培养是可行的。GV期卵母细胞复苏存活率高于MI期卵母细胞,但MI期卵母细胞冻融后发育潜能优于GV组卵母细胞。

Objective： To explore the best vitrification stage of human immature oocytes. Methods： A total of 502 suplurs immature oocytes （GV group, n=179 and M_I group, n=323） were obtained from patients who underwent intracytoplamic sperm injection （ICSI） cycles. Frozen＇thawed immature oocytes treated with in vitro maturation （IVM） in both groups were inseminated by ICSI. The injected oocytes were cultured in cleavage medium. The rates of survival, maturation, fertilization and early embryonic development were observed in these two groups. Results： Survival rate was significantly higher in GV group than in M_I group （83.24% vs 75.54%, P=0.045）. The available embryo rate was significantly lower in GV group than in M_I group （60.53% vs 78.67%, P=0.041）. There were no significant differences in the rates of maturation, fertilization, cleavage, day 3 good- quality embryos and blastocyst between the two groups （P〉0.05）. Conclusion： 1） The human immature oocytes derived from controlled ovarian hyperstimulation （COH） cycles can be well cryopreserved by using vitrification method because of high survival rate, fertilization rate, cleavage rate and available embryo rate. So these imma- ture oocytes should be fully utilized. 2） The immature oocytes at GV stage can be more effectively vitrified than that at the M_I stages. But developmental potential of immature oocytes in M_I group was superior to that in GV group.