Potential development to blastocyst of the surplus embryos from human embryo transfer

Objective To explore the developmental potential of the surplus embryos from human embryo transfer during IVF-ET cycles.Methods All embryos with non-pronucleus(0PN),a single pronucleus(1PN),a number of pronucleus(≥3PN) and 2 pronucleus delaying development in cleavage stage(2PN) were cultured into blastula by the sequential method.Results ① 314 Surplus embryos were collected and formed 152 blastulas(48.41%) after the sequential culture,among which 53(34.87%) were high-quality blastula.② The embryo grade on Day 3 was related to blastocyst rate.The higher embryo grade,the higher blastula formation(54.39%,52.39%,49.61% and 21.62%);③ Blastocyst formation rates of embryos in 1PN embryos,0PN embryos and D3 from blastocyst embryos classified Ⅲ had higher rates of blastula formation than D3 from blastocyst embryos classified beyond Ⅲ(P0.05).Conclusion Embryos of level Ⅲ and above in D3 are still opportunities for blastocyst formation.The 0PN,1PN embryo cleavage embryos developed from the D3 can continue to develop in high-quality,until after the formation of blastocysts,and then a pre-implantation genetic diagnosis.If the karyotype is aneuploid karyotype,then it should be frozen or transplanted first.The measures above can improve the oocyte retrieval in patients with accumulation of a single pregnancy,which can also provide resources for embryonic stem cell research.