Effect Of The Different Fertilization Time After HCG Injection On The Early Embryonic Development And Clinical Outcome Of Patients In In Vitro Fertilization-embryo Transfer

Objective: To investigate the effect of the different fertilization time after HCG injection on the early embryonic development and clinical outcome of patients in in vitro fertilization-embryo transfer(IVF-ET).Methods: Select a total of 200 patients undergoing IVF-ET, during December 2013 to October 2015, were devided into 4 groups according to the different fertilization time after HCG injection. Group A: fertilization happened in 38-39 hours(including 39 hours) after HCG injection; Group B: 39-40 hours(including 4 0 hours) after HCG injection; Group C: 40-41 hours(including 41 hours) after HC G injection; Group D:41-42 hours(including 42 hours) after HCG injection, 50 cases in each group. The normal fertilization rate, cleavage rate, the embryo utilization rate, the high quality embryo rate, the clinical pregnancy rate, the implantation rate, and the spontaneous abortion rate were evaluated among the 4 groups. Results: High quality embryo rate: Group A was lower than those of group C and group D, Group B was lower than that in group D(P<0.05,respectively); About the normal fertilization rate,The normal cleavage rate, the embryo utilization rate, clinical pregnancy rate, implantation rate and abortion rate; there were no obvious differences among the 4 groups(P>0.05,respectively).Conclusion: The different fertilization time after HCG injection in IVF-ET have effects on high quality embryo rate: during a certain time range(38-42 hours),as the increase of delayed fertilization time after HCG injection, high quality embryo rate is also increasing; The best fertilization time of patients in in vitro fertili- zation-embryo transfer was 40-41 hours after HCG injection in our reproductive center, during which can improve the clinical pregnancy rate, reduce the early abortion rate and get better clinical pregnancy outcome.