体外受精-胚胎移植周期中第3天移植胚胎细胞数与妊娠率的相关性

Relationship between the cell number of embryo transferred and pregnancy rate in IVF-ET cycle

目的探讨体外受精-胚胎移植（IVF-ET）周期中第3天移植的不同细胞数目的胚胎,其妊娠率有无差别;并进一步分析哪些分裂阶段的胚胎不适合于体外培养后第3天移植。方法以2004年1月至2006年6月在本中心接受IVF-ET治疗的788对夫妇,共792个周期为研究对象。ET后4周B超测到胎心搏动视为妊娠。将所有移植胚胎按细胞数目的不同分为4组：移植胚胎细胞数≤4（a组）;移植胚胎细胞数为5-（b组）;移植胚胎细胞数为7-9（c组）;移植胚胎细胞数≥10（d组）。通过计数胎心数标定每一组胚胎的种植率,分析4组胚胎种植率有无差异。结果c组胚胎其种植率（34.0%）显著高于其他3组（P〈0.05）;其中8细胞胚胎的种植率最高（34.8%）,其次是9细胞胚胎（34.3%）和7细胞胚胎（31.6%）,再次是10细胞的胚胎（14.3%）,最后是5-6细胞胚胎（8.7%）;在对所移植的胚胎全部种植或全部不种植的周期分析中,移植≤4细胞胚胎或移植≥11细胞胚胎发生种植的可能性为0。结论在IVF-ET周期中第3天移植7-9细胞的胚胎其妊娠率显著高于移植其他细胞数的胚胎;选择胚胎时应首选8细胞的胚胎,然后是9、7、10细胞的胚胎,最后是5-6细胞胚胎;体外培养第3天≤4或≥11细胞胚胎不适合移植。

Objective： To investigate the relationship between the cell number of day 3 embryo clinical pregnancy rate in IVF-ET cycle, and how to select the best embryos on day 3 of transfer. transferred and the culture for embryo Methods ： This study involved 788 patients and a total of 792 IVF and ICSI cycles from January 2004 to June 2006. The embryos transferred on day 3 of culture were divided into four groups based on the cell numbers： group a, the cell numbers of embryo transferred ≤4; group b, the cell numbers of embryo transferred was 5-6; group c, the cell numbers of embryo transferred was 7 -9; group d, the cell numbers of embryo transferred ≥10. Pregnancy was confirmed by ultrasound 4 weeks after embryo transferred. The implantation rate in each group was calculated by taking count of the numbers of fetus heart and the difference among groups was analyzed. Results： Embryos in group c resulted in the highest implantation rate （34.0%）, higher than those in other 3 groups （P〈0. 05）. The embryos with 8 cells resulted in the highest implantation rate （34.8%）, followed by the embryos with 9,7,10 cells （34.3%, 31.6%, 14.3%, respectively）, while the implantation rates of the embryos with 5-6 cells were poor （8.70%）. In those cycles which implantation rate of embryos transferred was 0 or 100%, the implantation rate of embryos with cell numbers≤4 or ≥11 at day 3 was 0. Conclusions： The pregnancy rate is closely related to the cell number of embryo transferred. When embryos were transferred on day 3 of culture, the highest pregnancy rate was found in the embryos with 7-9 cells. The embryo with 8 cells at day 3 should be the first choice for embryo transfer and the embryo with 9 or 7 cells ranks second, followed by the embryo with 10 cells, the embryos with 5-6 cells. The embryos with ≤4 or ≥11 cells are not eligible for fresh transfer cycle.