RESUMEN
BACKGROUND: The aim of the study is to compare the incidence of eSET (elective single embryo transfer) and DET (double embryo transfer) and their results about live birth and twin pregnancies between first and second IVF/ICSI cycles, in a selective population. These data allow analysing whether the extension of elective single embryo transfer in the second cycle is efficient. PATIENTS AND METHODS: Retrospective study about embryo transfers performed in first and second IVF/ICSI cycles in the IVF unity (CHU Clermont-Ferrand) between 1 January 2004 and 31 December 2006. Women belonging to couples considered have less than 36 years. On the second day of embryo development, at least two good quality embryos have been observed. After information about eSET and DET, couples give their written consent to the transfer of one or two embryos. Couples who have no live birth at the end of the first cycle have been followed up for the second cycle whether they correspond to the inclusions criteria. Analysis is performed with live birth rates by tentative (overall rate) and after one or two embryo transfer, cumulative live birth rate (including fresh and frozen embryo transfer, and twin pregnancy rate. RESULTS: An embryo transfer at the first IVF/ICSI cycle (report eSET/DET=0.5) has been performed for 513 patients. The overall cumulative live birth rate is 37.1%, without significant difference between eSET and DET (36.2% vs 35.7%, p=ns). The twin pregnancies rate is 12% (including 0% in eSET vs 24% in DET, p<0001). Two hundred and five patients have a second IVF/ICSI cycle (92.3% in DET and 7.7% in eSET). The overall cumulative live birth rate is 34.1% without difference between eSET and DET (31.3% vs 34.3%). The twin pregnancies rate is 22.5% and it is significantly higher compared with the first attempt (including 0% in ESET and 24.6% in DET). DISCUSSION AND CONCLUSION: The increased twin pregnancies rate during the second cycle is explained by the higher rate of DET. This may be explained by the non-acceptance by couples of a new eSET, despite acceptable results for live birth rate. We have to search for solutions to encourage its development like the reimbursement of more cycles when eSET is performed, or with regulations as in Belgium, because the information to the couples is not efficient.
