Outcomes of day-1, day-3, and blastocyst cryopreserved embryo transfers

The optimal developmental stage for cryopreserving embryos in IVF-ET remains controversial. Our study demonstrates that besides an improvement in postthaw survival rate for day-1 and blastocyst cryopreserved ET over day-3, all three groups attained statistically similar implantation, clinical pregnancy, multiple, twinning, and male gender rates.