How to demonstrate that eSET does not compromise the likelihood of having a baby?

BACKGROUND In several randomized studies, elective single embryo transfer (eSET) has proven its effectiveness in reducing twin pregnancy rates while obtaining acceptable overall pregnancy rates. However, there is no outcome measurement consensus to evaluate the effectiveness of eSET versus double-embryo transfer (DET). METHODS This study evaluated whether or not adopting an eSET strategy instead of a DET strategy lowers the probability of having at least one live-born infant in good prognosis couples. Seven hundred and twenty-six couples were divided into two groups. The retrospective arm of the study was undertaken on the first group of couples (n = 483, DET group) and the prospective arm performed on the second group of couples (n = 243, SET group). In these specific populations, the probability of a woman having at least one live-born infant and the probability that one embryo utilized leads to a child were the main outcome measures. RESULTS The probability of a woman having at least one live-born infant was 60.5% in the DET group compared with 60.8% in the SET group. The probability of a live-born child per embryo utilized was not significantly different between the SET and the DET groups, 18.9% and 17.6%, respectively. In addition, the cumulative multiple live birth rate was significantly lower in the SET compared with the DET group. CONCLUSIONS In this observational study, using appropriate cryopreservation techniques, the chance of delivering a live baby, per utilized embryo, in an elective SET strategy is as good as that for DET.