[Prospective evaluation of elective single-embryo transfer versus double-embryo transfer following in vitro fertilization: a two-year French hospital experience].

Objective: Multiple embryo transfer is responsible for a high rate of multiple pregnancies (ICSI), with subsequent risks of premature birth and perinatal death. This prospective non randomized study aimed to assess the ability of an elective single-embryo transfer (eSET) policy to reduce the twin pregnancy rate, compared to a double embryo transfer (DET) approach.

Patients And Methods: Between March 2005 and May 2006, 180 eligible women were proposed to benefit from an eSET transfer rather than a DET. Inclusion criteria were (i) age less than 37 years old; (ii) at least two good quality embryos available (three to five cells at day 2 or six to nine cells at day 3; less than 20% fragmentation and the absence of multinucleates blastomeres), after IVF or ICSI and (iii) no more than one previous failed treatment cycle. Outcome analysis included cycles with frozen-thawed embryo transfer (FET).

Results: According to patients' decision, 107 and 73 women had an eSET (59.4%) and a DET (40.6%) respectively. No differences were found between eSET and DET groups regarding demographics and biologicals parameters. The clinical pregnancy rate (PR) per transfer was 43.9% in eSET group and 57.5% in DET group (p=0.07). The twin pregnancy rates were 0 and 14.3%, in eSET and DET groups, respectively (p=0.007). The cumulative PR per patient, including the outcome of performed FET cycles, was 63.6% in eSET group and 61.6% in DET group. In this case, the cumulative twin pregnancy rates were 2.9 and 15.6% in eSET and DET groups, respectively (p=0.02).

Discussion And Conclusion: Our data show that in a selected population of women, transferring one fresh embryo and then, if required, one or two frozen-thawed embryos significantly reduces the twin pregnancy rate without decreasing the overall pregnancy rate. This study supports the policy of eSET in this subgroup of patients.