Single blastocyst transfer: Contemporary experience

Recent studies demonstrated an overwhelming success in single blastocyst transfer (SBT): implantation rates (IR) were 60.9%-70.5% and pregnancy rates (PR) were 60.9%-76% while the multiple pregnancy rates (MPR) were 0%-3.2%. Most of these studies involved good prognosis patients not more than 37 years of age. The results indicated that SBT decreased the number of multiple pregnancies while maintaining desirable pregnancy outcomes. However, SBT and cryopreserved single blastocyst transfer (cSBT) in the field of in vitro fertilization (IVF) are still in their infancy. Guidelines for the number of blastocysts being transferred and the techniques have not yet been standardized. The method to estimate the most viable blastocyst has not yet been proposed. The success of SBT also was found to be highly associated with the technique and patients' and clinicians' perceptions toward it.