Pregnancy and twinning rates using a tailored embryo transfer policy

A tailored embryo transfer policy based on the prognostic profile of the couple was prospectively evaluated. Single-embryo transfer (SET) was performed, followed by double-embryo transfer (DET) in frozen-thawed embryo transfer cycles in women with a good prognosis ( <35 years, first cycle, ⩾1 top-quality embryo). DET was performed in both fresh and frozen cycles in women with an intermediate prognosis ( <35 years, first cycle and no top-quality embryo available, or <35 years and ⩾1 failed cycles, or 35-38 years). Triple-embryo transfer (TET) in both fresh and frozen cycles was performed in women with a poor prognosis (⩾39 years). The cumulative ongoing pregnancy rate in the cycles of women with a good prognosis was 43% with a multiple pregnancy rate of 2%, in the cycles of women with an intermediate prognosis 27% and 23% and in the cycles of women with a poor prognosis 18% and 13%, respectively. These findings can be used to guide current practice: i.e. performing SET in women with a good prognosis and TET in women with a poor prognosis. The embryo transfer strategy in women with an intermediate prognosis requires further improvement, possibly by refining the prognosis according to the ovarian response after ovarian stimulation