Comparison of 2 kinds of human cleaved embryos cryopreservation

Objective To compare the outcome of the vitrification using cryotop to the slow-freezing method for human cleaved embryos cryopreservation.Methods In the in vitro fertilization-embryo transfer cycles,supernumerary embryos were cryopreserved by vitrification using cryotop or the slow-freezing method.The embryo survival rate,embryo score,pregnant rate and implantation rate were compared after thawing.Results In 66 vitrified embry othaw cycles,253 vitrified embryos were thawed,and 192(75.89%) of them survived after the thawing.In 66 women,187 embryos were transferred,and 26(39.39%) of them got clinically pregnant.In the pregnant women,2(7.69 %) suffered from miscarriage.As to slow-freezing method,in 105 embryo thaw cycles,589 embryos were thawed,327(55.52 %) of them survived,and 303 embryos were transferred in 105 cycles.In 32(30.47%) clinically pregnant women,4(12.5%) were miscarried.The embryo survival rate,embryo score,were higher in vitrification group than those in slow-freazing group(P0.01,P0.05).Conclusion It is a good method in embryos cryopreservation of the vitrification using cryotop.The survival rate and better-embryo rate of vitrified embryos are higher than those of traditional slowly-frozen embryos.