Evaluation of the Embryo Quality for Elective Single Embryo Transfer

为了提高体外受精成功率，我们开发了优化胚胎选择的技术，以带弹性为选择标准，在确保胚胎不损伤的同时，具有最高的着床潜力。首先，PN期受精后出现“带状硬化”现象，杨氏模量随着胚胎发育逐渐降低。膨化囊胚的质量评价表明，膨化囊胚的质量也可以从弹性参数来评价。此外，观察发现，在体内形成的胚胎在各阶段的ZPs均明显硬于体外形成的胚胎。我们检测了IVF治疗后ZP弹性变化与胚胎质量的相关性，结果表明MTS-eSET后的妊娠率与双胚胎移植后的妊娠率几乎相同。从理论上和实验上也证实了MTS试验不会对胚胎造成任何损害。此外，我们研制了一种低温纳米孔玻璃化容器，低浓度CPA溶液不含血清，可以成功地冷冻保存小鼠和人胚泡。

To enable improved success rate of IVF, we developed the technology to optimize embryo selection, having the highest implantation potential while ensuring no damage to embryos using zona elasticity as selection criteria. First, "zona hardening" was demonstrated mechanically following fertilization at the PN stage, Young's modulus decreased gradually as the embryo developed. Evaluation of the quality of expanded blastocysts(EPB) shows that the quality of EPBs could also be evaluated from elasticity parameters. Furthermore observations indicated that ZPs of embryos generated in vivo were significantly harder than those of embryos generated in vitro at each stage. We examined the correlations between subsequent ZP elasticity changes after IVF treatment and quality of embryos and the results showed that the pregnancy rate after MTS-eSET was almost the same with that after double-embryo transfer. It was also examined that both theoretically and experimentally the MTS test does not cause any damage to embryos. Furthermore, we developed a cryo-nano-hole vitrification container with a low concentration of CPA solution with no serum and mouse and human blastocysts can be cryopreserved successfully.