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

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5~6(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。

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

Objective: To investigate the relationship between the cell number of day 3 embryo transferred and the clinical pregnancy rate in IVF-ET cycle,and how to select the best embryos on day 3 of culture for embryo transfer.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.