Human Embryo Blastocyst Culture And Relative Factors Research

Background: Traditional Invitro fertilization and embryo transfer(IVF-ET)procedure transfer embryos after 2~3days invitro culture,when the blastomeres count only 4~8cells. The following embryo implantation rates are 10-30%. The blastocysts transfer will improve embryo selection and decrease the transfer number if we can advance the invitro culture times. Other merits are: synchronization between emdometrium and embryos,higher pregnancy rates,no need assist hatching and so on. The first successful attemptation to produce higher-quality blastocysts was through co-culture,which involves complex laboratory techniques.More recently,sequential culture was proved at least as good as coculture. Object: Here we try to find the relationship between the 3th day embryo cell number and quality score and blastocyst formation ,the different blastulation rates of three mediums, and the prognostic effect of excessive embryos. Metheds: In this study,the day 3 surplus embryos were transfered to designed mediums contain 10%SSS for advanced culture.Three culture mediums were IVC-Three Medium,Blastocyst Medium or HTF Medium. The embryos progressingcondition were conserved every day,the medium was refreshed on day 6.The first three days clinical trial was according to the routine of Sir Run Run Shaw Hospital 1VF laboratory,and the later experiment procedure went on by Bongso blastocyst culture hand book. Results: 18 volunteers provided 54 embryos after day 3 transfer,forming 16 blastula,12 full expanded,3 hatched or hatching,blastulation rates were 29.6%, divided into 2 single ,2 twin and 2 triple.18 cases transfered 61 embryos,implantation rate19.7%,clinical pregnancy rate 33.3%. The remarkable result was the positive correlation teween the day 3 embryo cell number and blastulation rate which elevated straightly with cell number increasing(r=0.99, P<0.01).When cell number reached more than 8,the rate attain 50%. And the relationship between embryo quality score and blastulation was worth of noticing(34.9% for 1~3 degree versus 9.1% for 3 ~4degree),al though the result had no statistic value(X2=1.69, P>0.05). The blastulation rate of IVC-Three Blastocyst Medium was significantly higher than that of Blastocyst Medium and HTF(56.1% versus 19.4% versus 12.7%after standardized,X2=8.92 , P<0.025). The colleration of surplus embryo blastulation and clinical pregnancy was also concerned,but no statistic signification(4/10 versus 2/8, P>0.05). We still have little awknowledge about the blastocyst quality mesure,more laboratory reseach need following.Conclusion:!.Advanced culture of surplus embryo will reach some blastula.2.The day 3 embryo cell number and quality score have some indication to blastulation.3. The blastulation rate of IVC-Three Blastocyst Medium was significantly higher,which is a potential clinical culture medium.4.Transfer 1-2 blastocyst is an effective method to avoid multiple pregnancy and reduce complication.