Elective single-embryo transfer in oocyte donation programmes: should it be the rule?

The aim of this study is to compare the cumulative clinical pregnancy and live birth rates (fresh embryo transfers followed by frozen--thawed embryo transfers from the same stimulated cycle) between single-embryo transfer (SET) and double-embryo transfer (DET) in an oocyte donation programme. A retrospective analysis of the outcome in 1139 recipient fresh cycles (1073 from DET and 66 from SET) with at least three available embryos for transfer was performed. The clinical pregnancy rates were similar after SET (45.5%, 30/66) and DET (57.1%, 613/1073), whereas the multiple pregnancy rate was 0% and 39.5% for SET and DET, respectively. After evaluating the results using the Kaplan--Meier survival analysis in a period of 1 year, no statistically significant differences were observed in the cumulative clinical pregnancy and live birth rates (SET 82.8% and 76.4% versus DET 77.2% and 63.7%). The results indicate that for women who have at least three available embryos in oocyte donation programmes, one single embryo should be transferred as no significant decrease in the success rate is observed and multiple pregnancy can be avoided. [ABSTRACT FROM AUTHOR]