目的　在IVF中提高妊娠率 ,减少多胎妊娠 ,同时选择生存能力强的、质量好胚胎进行移植 ,对于IVF病人和医生都具有重要的意义。本研究选择 4 0例在IVF中进行囊胚移植的患者作为研究对象 ,同时随机选择 4 0例在IVF中D1- 3时期进行胚胎移植的患者作数据对照。结果　囊胚移植周期的临床妊娠率为 5 7 5 % ,囊胚形成率为 74 6 % ,当受精率大于90 %和囊胚转化率大于 77 6 %时 ,妊娠率明显提高。而本研究中常规D2 - 3期胚胎移植的临床妊娠率为 32 5 %。结论　囊胚期移植时 ,因发育阻滞及染色体有可能异常的胚胎未能移入宫腔 ,从而保证移植进的胚胎质量 ,进一步提高临床成功率 ,也为开展种植前遗传学诊断创造条件 ,为胚胎干细胞的定向培养打下基础 ,具有十分重要的应用前景。 Objective To improve the pregnancy rate in IVF, reduce multiple pregnancy, and select the survival of good, good quality embryos for transplantation, IVF patients and doctors are of great significance. In this study, 40 patients with blastocysts in IVF were enrolled in this study. Forty patients with embryo transfer during D1-3 in IVF were randomly selected as data controls. Results The clinical pregnancy rate was 57.5% and the blastocyst formation rate was 74.6%. The pregnancy rate was significantly improved when the fertilization rate was over 90% and the blastocyst transformation rate was over 77.6%. However, the clinical pregnancy rate of routine D2 - 3 embryo transfer in this study was 32.5%. Conclusion During the blastocyst stage, the embryos that are blocked by development and may be abnormal in their chromosomes can not move into the uterine cavity, thus guaranteeing the quality of the transplanted embryos and further improving the clinical success rate, and also provide the conditions for pregenetic genetic diagnosis. Oriented cultivation of embryonic stem cells laying the foundation, has a very important application prospects.