Frozen-thawed embryo transfer cycles in China: clinical outcomes of two and three multicellular embryos transfers

To analyze the clinical outcomes of frozen embryo transfer (FET) cycles when two or three multicellular embryos were transferred in Chinese women. A retrospective study was conducted to analyze 980 FET cycles performed between January 2007 and October 2010. Two (785 cycles) or three (195 cycles) multicellular embryos were transferred. Both in patients under 35 years ( = 776) and those aged 35 to 39 years ( = 169), the transfer of two versus three multicellular embryos results in similar clinical pregnancy rates (CPR), implantation rates (IR) and live birth rates (LBR). In both age groups, the multiple pregnancy rate (MPR) was significantly higher in the three-embryo groups. Among women over 40 years of age ( = 35), there were no differences in the CPR, IR, MBR or LBR between the two groups Transferring two instead of three multicellular embryos in patients under 40 years old significantly decreases the risk of MPR without compromising PR, IR and LBR. In the age group above 40, transferring two instead of three multicellular embryos did not decrease PR, IR, MBR or LBR. Transferring more embryos when a patient had more unsuccessful cycles was not warranted in all patients.