Evaluation of the new closed vitrification system Rapid-i
The results of the vitrification cycles showed a high clinical pregnancy rate (CPR) of 48.6%, similar to the results of fresh blastocyst eSET, 53.6%, and a survival rate of 88%. However, the high multiple pregnancy rate (MPR) when more than one blastocyst was transferred was a reason for concern. The Ottawa Fertility Centre therefore decided to determine the effectiveness of combining a fresh single elective blastocyst transfer with a single (S-FET) compared to a double (D-FET) vitrified embryo transfer.
New transfer strategy
31 patients that had a fresh eSET returned for an additional transfer (FET) of a vitrified/warmed blastocyst. 17 of the 31 patients had a single frozen embryo transfer (S-FET), and 14 had a double frozen embryo transfer (D-FET).
The clinic concluded that ”transferring one fresh and one vitrified blastocyst at a time can lead to very high cumulative pregnancy rates while maintaining very low multiple pregnancy rates”.
A.P. Tartia et al. Poster presentation. CFAS 2012.