Relationship between Embryo Morphology on Day3 of Development after Oocyte Retrieval and Embryo Implantation

Objective: To investigate the relationship between embryos morphology on day3 of development and implantation rates of embryo. Methods: 62 cycles of in vitro fertilization and embryo transfer(IVF-ET) of 35 years women were classified into two groups:implantation group(implantation rate was 100%,30 cycles/56 embryos) and un-implantation group(implantation rate was 0%,32 cycles/64 embryos).All morphologic characteristic of embryo on day3 of development were analyzed including blastomere quantity,size,nucleus,color,granulation,the ratio and type of fragments,granular area vacuoles,the thickness and shape of zona pellucida. Results: A statistical difference was observed in the rate of embryo development,blastomere nuclei quantity and the type of fragmentation between the two groups(P 0.05).In implantation group,71.4%(40/56) transferred embryos showed 7～8 cells on day3 57.1%,blastomeres showed at least one visible nucleus,30.4% embryos have one nucleus in each blastomere,41.1% embryos showed fragmentation of T1 pattern.The discriminant analysis indicated that the number of blastomeres and fragmentation pattern were more important than the nucleus and size of blastomeres,fragmentation number.And the discriminant accordance rate of embryo implantation was 70.0%. Conclusions: The rate of blastomere development and fragmentation type are principal factor for selecting embryo transferred and 8-cell and 7-cell on the day3 after oocyte retrieval had better implantation potential.It should pay more attention to the fragmentation type than fragmentation quantity.