Aim: To confirm whether women who choose to have one fresh embryo transferred and one frozen-and-thawed embryo when needed can dramatically reduce the possibility of a multifetal pregnancy while giving themselves a better chance of achieving pregnancy.
Methods: We enrolled 685 patients who were undergoing assisted reproductive technology (ART) treatment at our clinic between January 2005 and December 2008. None of the patients had a history of ART treatment, and they received either a double-embryo transfer (DET) or single-embryo transfer (SET) during this period. The outcomes of the ART and the pregnancy rates per patient were evaluated for both groups and comparisons were made.
Results: The mean age was 35.7 +/- 0.2 years (mean +/- standard error of the mean) for all patients (n = 583) who received a fresh embryo cycle of DET. In contrast, the mean age (34.3 +/- 0.4) of all patients (n = 102) who received a fresh- or thawed-embryo transfer cycle of SET was significantly younger than the average age in the DET group (P < 0.05). The per-patient overall pregnancy rate in the SET group was an estimated 35.3%, which was significantly higher than that in the DET group (P = 0.02). However, the multifetal pregnancy rate for the DET group was significantly higher than that for the SET group (P < 0.01).
Conclusion: We demonstrated that women who choose to have one fresh embryo transferred and one frozen-and-thawed embryo when needed, can dramatically reduce their possibility of a multifetal pregnancy while giving themselves a better chance of achieving pregnancy.