Clinical application of frozen-thawed embryo transfer

Objective To research into the clinic application of transferring frozen-thawed embryos and improve pregnancy rate of in vitro fertilization-embryo transfer(IVF-ET).Methods The surplus embryos after in vitro fertilization and embryo transplantation (in 49 cases) were all cryopreservated.Slow freezing and rapid thawing method were used.Results Among the 49 cases who had received cryopreservation thawed embryo transplantation for 53 cycles,11 cases achieved clinical pregnancy (with the rate of 20.8%).Among the 53 cycles,32 cases received natural cycle transplantation and 7 of them achieved clinical pregnancy (with the rate of 21.9 %);5 cases received hormone substitution transplantation and 1 of them achieved clinical pregnancy (with the rate of 20 %);16 cases received Clomiphene citrate(CC)/hMG stimulating cycles and 3 of them achieved clinical pregnancy (with the rate of 18.8 %).Conclusion Frozen-thawed embryo transplantation(FET) can increase the chance of accumutive pregnancy and decrease the occurrence of multipregnancy and the syndrome of excessive ovary stimulation.