Comparison of elective single cleavage-embryo transfer to elective single blastocyst-embryo transfer in human IVF-ET

Objective: This study was carried out to compare the clinical outcome of elective single cleavage-embryo transfer (eSCET) to that of elective single blastocyst-embryo transfer (eSBET) in human IVF-ET. Methods: This study was a retrospective study which analyzed for 614 women who visited the Daegu Maria Clinic from August 2008 to December 2009. All were under 37 years old and had more than 8 mm of endometrial thickness on the day of hCG administration and at least one good quality embryo on day 3. The eSCETs were performed on day 3 (n=450) and the eSBETs were conducted on day 5 (n=164). Results: The numbers of retrieved oocytes, fertilized oocytes, and day 3 good quality embryos were significantly lower in the eSCET group (12.1${\pm}$6.0, 8.2${\pm}$4.6, and 4.2${\pm}$3.1, respectively) compared to the eSBET group (16.7${\pm}$7.2, 12.1${\pm}$5.0, and 8.5${\pm}$4.5, respectively; p