Effect of Embryo Transferred Number on the Clinical Outcome in Short Term IVF/ICSI

Objective:To investigate the impact of the different embryo transferred number on the clinical pregnancy rate and the multiple pregnancy rate.Methods:A total of 1 463 cycles that performed the first short term IVF/ICSI treatment in the patients aged 35 years were selected from Jan.2002 to Oct.2004.It was divided into 3 groups,2-embryo group(84 cycles)and 3-embryo group(716 cycles)from Jan.2002 to Sep.2003,2-embryo group(663 cycles)from Oct.2003 to Oct.2004.The numbers of the available transferred embryo,the implantation rate,the clinical pregnancy rate and the multiple pregnancy rate were compared among 3 groups.Results:The implantation rate and the incidence of singleton were similar between 2-embryo group and 3-embryo group(20.62% vs 14.88%,20.62% vs 21.66%,P 0.05;27.19% vs 20.99%,27.19% vs 29.42%,P 0.05).The number of the available transferred embryo and the clinical pregnancy rate in 3-embryo group was significantly higher than those in 2-embryo group respectively(7.77±3.70 vs 4.62±4.73,7.77±3.70 vs 6.94±3.91,P 0.05;42.96% vs 25.93%,42.96% vs 39.06%,P 0.05).However,the multiple pregnancy rate per transfer in 2-embryo group was significantly lower than that in 3-embryo group(4.94% vs 15.49%,10.06% vs 15.49%,P 0.05).Conclusion:In short term IVF/ICSI protocol,the reduction of the transferred embryo number may decrease the clinical pregnancy rate,but the transfer of two embryos can reduce the incidence of multiple pregnan-ciese fficiently.