Objective: To evaluate implantation of day 5 and day 6 vitrified and slow-frozen blastocysts. Design: Retrospective analysis comparing two cryopreservation techniques. Setting: Private IVF clinic. Patient(s): Five hun...Objective: To evaluate implantation of day 5 and day 6 vitrified and slow-frozen blastocysts. Design: Retrospective analysis comparing two cryopreservation techniques. Setting: Private IVF clinic. Patient(s): Five hundred eight cryopreserved embryo transfer candidates. Intervention(s): Supernumerary day 5 and day 6 blastocysts were vitrified or slow-frozen and transfered after warming or thawing. Main Outcome Measure(s): Comparison of two cryopreservation techniques with respect to survival rate, implantation, and pregnancy rates of day 5 and day 6 blastocysts. Result(s): In 254 vitrified transfer cycles, survival, embryonic implantation, and clinical pregnancy rates for day 5 blastocysts were 95.9% , 33.4% , 48.7% , respectively, and for day 6 blastocysts 97.5% , 25.9% , 42.8% . In 254 slow-frozen transfer cycles, survival, embryonic implantation, and clinical pregnancy rates for day 5 blastocysts were 91.4% , 29.6% , 42.8% , respectively, and for day 6 blastocysts 94.8% , 28.2% , 43.1% . Overall there was a slightly, but not significantly, higher outcome regarding implantation and clinical pregnancy with the use of day 5 blastocysts (31.3% and 45.4% , respectively) versus day 6 blastocysts (26.7, and 42.9% , respectively). Conclusion(s): Vitrification technique yields the same implantation and pregnancy rate as slow-frozen blastocyst transfers. Slow growing embryos can be cryopreserved on day 6, because they yield a satisfactory survival, implantation, and pregnancy rate.展开更多
文摘Objective: To evaluate implantation of day 5 and day 6 vitrified and slow-frozen blastocysts. Design: Retrospective analysis comparing two cryopreservation techniques. Setting: Private IVF clinic. Patient(s): Five hundred eight cryopreserved embryo transfer candidates. Intervention(s): Supernumerary day 5 and day 6 blastocysts were vitrified or slow-frozen and transfered after warming or thawing. Main Outcome Measure(s): Comparison of two cryopreservation techniques with respect to survival rate, implantation, and pregnancy rates of day 5 and day 6 blastocysts. Result(s): In 254 vitrified transfer cycles, survival, embryonic implantation, and clinical pregnancy rates for day 5 blastocysts were 95.9% , 33.4% , 48.7% , respectively, and for day 6 blastocysts 97.5% , 25.9% , 42.8% . In 254 slow-frozen transfer cycles, survival, embryonic implantation, and clinical pregnancy rates for day 5 blastocysts were 91.4% , 29.6% , 42.8% , respectively, and for day 6 blastocysts 94.8% , 28.2% , 43.1% . Overall there was a slightly, but not significantly, higher outcome regarding implantation and clinical pregnancy with the use of day 5 blastocysts (31.3% and 45.4% , respectively) versus day 6 blastocysts (26.7, and 42.9% , respectively). Conclusion(s): Vitrification technique yields the same implantation and pregnancy rate as slow-frozen blastocyst transfers. Slow growing embryos can be cryopreserved on day 6, because they yield a satisfactory survival, implantation, and pregnancy rate.
