Clinical application of cryopreservation thawed embryos

Objective To accumulate experience of cryopreservation thawed embryo transfer in vitro fertilization. Methods The surplus embryos after in vitro fertilization and embryo transplantation (in 20 cases) were all cryopreservated. Given invalidated pregnancy, they would be thawed in a later cycle for another transplantation. Results Among the 20 cases who had received cryopreservation thawed embryo transplantation for 20 cycles, 7 cases achieved clinical pregnancy (with the rate of 35%). Out of the 20 cases, 13 cases received natural-cycle transplantation and 5 of them achieved clinical pregnancy (with the rate of 38.5 %); 7 cases received hormone substitution transplantation and 2 of them achieved clinical pregnancy (with the rate of 28.5 %). In the first case of cryopreservation thawed embryo pregnancy, a boy infant was delivered after 38 weeks conception and the neonate developed well. Conclusion Cryopreservation thawed embryo transplantation can increase the chance of accumutive pregnancy while curb the occurrence of multi pregnancy and the syndrome of excessive ovary stimulation.