Our research used this laser system and its precise measurement software to make a all - round study on the relationship of zona pellucida thickness / hardness variation of human embryos and clinical pregnancy outcome following in vitro fertilization treatment and the application of laser thinning in assisted hatching . the purpose of this study was to try to provide the basic rationale for assisted hatching and an alternative assisted hatching method 本研究即为应用这种激光系统及其精确的测量软件,对zpt 、 zptv与妊娠结局的关系、体外培养胚胎透明带硬度的变化及激光薄化透明带进行辅助孵出的临床应用进行综合研究探讨,旨在为辅助孵出的病人选择、方法选择提供基础与临床理论依据。