Developmental Potential of Embryos Affecting Human Blastocyst Formation in Vitro

Objective:To investigate the effect of blastomere number and quality classification on human blastocyst formation in vitro. Methods:Through sequential culturing the D3 discarded embryos to D5-7,the blastocyst formation was observed and the relationship was detected between the D3 embryo cell number,quality grade and the blastocyst quality,the formation of the high-quality blastocyst providing the academic basis for the blastocyst transplantation. There were 406 D3 discarded embryos entered this experiment,where were cultured with CCM,and observed daily until the fertilized embryo of the first D5-7. Results:One hundred and two blastocysts were formed including 28 high-quality blastocysts using the blastocyst grade standard from Gardener. The blastulation rate was 25.12%. Among 64 patients developed blastocysts,32 patients pregnancied. The pregnancy rate was higher in patients with blastocysts than that without blastocysts (50% vs 28.79%,P 0.05). Conclusion:The blastalation rate was positively correlative with the D3 embryo cell numbers. The blastulation rate was higher in the embryos with I-II+ degree than that with III-IV degree.