Objective: To explore the causes of oocyte vitrification and its application in assisted reproduction.
Methods: We retrospectively analyzed the data of 26 patients with 27 cycles of oocyte vitrification cryopreservation undergoing intracytoplasmic sperm injection (ICSI) and embryo transfer between January, 2008 and October, 2018. The causes of oocyte vitrification and the outcomes of ICSI and clinical pregnancy were analyzed.
Results: The causes of oocytes vitrification included mainly azoospermia or severe spermatogenesis disorder of the husband, failure to obtain sperms from the husband, failure of the husband to be present on the day of oocyte retrieval and acute diseases of the husband to not allow sperm collection. A total of 274 oocytes were frozen in 27 oocyte retrieval cycles, and 217 eggs were thawed in 19 cycles with a survival rate of 81.11% (176/217). The normal fertilization rate, cleavage rate and high-quality embryo rate was 74.81% (98/131), 89.80% (88/98) and 36.73% (36/98), respectively. Fifteen patients underwent embryo transfer, and the clinical pregnancy rate and live birth rate was 53.33% (8/15) and 33.33% (5/15), respectively. Compared with patients below 35 years of age, the patients aged above 35 years had significantly lower oocyte survival rate after thawing (82.76% vs 74.42%, P=0.211), clinical pregnancy rate (77.78% vs 16.67%, P=0.041) and live birth rate (55.56% vs 0, P=0.044).
Conclusions: Oocytes vitrification can be used as a remedy for infertile couples who fail to provide sperms due to male factors on the day of oocyte retrieval. Vitrification of the oocytes does not significantly affect the fertilization rate or the clinical pregnancy rate. The survival rate of the thawed oocytes is related to the age of the wife, and an age younger than 35 years can be optimal for achieving favorable clinical pregnancy outcomes after oocyte vitrification.
目的: 探讨人卵子玻璃化冷冻的原因及其技术在辅助生殖中的可行性和临床应用价值。
方法: 回顾性研究2008年1月~ 2018年10月在南方医科大学南方医院生殖医学中心行卵子玻璃化冷冻的26例患者共27个取卵周期，分析卵子玻璃化冷冻原因、卵子解冻后受精情况及临床妊娠结局。
结果: 26例患者27个取卵周期共冷冻卵子274枚，卵子冷冻原因主要包括取卵日男方精子数量及质量差无可用精子、男方处于各种疾病急性期不适宜取精及男方因各种原因未能到场取精等。共19个周期行卵子解冻，该19个周期共冻存卵子217枚，解冻后存活176枚，卵子解冻存活率81.11%，其中131枚卵子解冻后行卵胞浆内单精子注射，正常受精98枚，正常受精率74.81%；卵裂88枚，卵裂率89.80%（88/98）；共形成可移植胚胎53枚，其中优质胚胎36枚，优质胚胎率36.73%（36/98）。15个移植周期共移植胚胎27枚，临床妊娠率为53.33%（8/15），活产率为33.33%（5/15）。随患者年龄增加，与 < 35岁组相比，≥35岁组患者卵子复苏率（82.76% vs 74.42%，P=0.211）、临床妊娠率（77.78% vs 16.67%，P=0.041）及活产率（55.56% vs 0，P=0.044）均呈下降的趋势。
结论: 卵子玻璃化冷冻可作为不孕夫妻取卵当日因男方因素不能提供精子患者的临床补救措施；卵子玻璃化冻融后的受精率、临床妊娠率结局良好，卵子复苏率与年龄存在相关性，女性≤35岁者冻卵能够获得满意的临床妊娠结局。
Keywords: assisted reproductive technology; oocytes; vitrification.