Perinatal outcome of blastocyst transfer with vitrification using cryoloop: a 4-year follow-up study

Objective: To evaluate perinatal outcome of ultrarapid vitrified blastocyst transfer. Design: Retrospective study. Setting: Private IVF clinics. Patient(s): One hundred eight women, who delivered 147 babies. Intervention(s): Supernumerary blastocysts were vitrified using cryoloop method and transferred after warming. Main Outcome Measure(s): Survival rate of blastocyst after vitrification, implantation and pregnancy rates, neonatal outcome and congenital birth defects. Result(S): A total of 1,129 vitrified blastocysts from 435 cycles were warmed and 967 survived (85.7%). In 413 cycles of transfer, the pregnancy, implantation, and abortion rates were 44.1%, 29.0%, and 22.0%, respectively. Of 108 deliveries, 34 (32.9%) were multiple pregnancies and 20 were preterm (18.5%). Out of 147 children born, 50.3% were male and congenital birth defects were observed in 1.4%. These results were similar with those of fresh blastocyst transfer program. Conclusion(s): The vitrification of blastocyst using cryoloop is a simple, easy, and quick method. This technique yields the same high pregnancy and implantation rates as fresh blastocyst transfer. Congenital defect rate in this study was similar to fresh blastocyst transfer, proving the method to be safe. (c) 2005 by American Society for Reproductive Medicine.