PURPOSE: Cryopreservation of blastocysts, especially those subjected to the trauma due to blastomere biopsy for the purposes of pre-implantation genetic screening (PGS), requires significant optimization. Laboratory and clinical outcomes were compared to determine the effect of two different cryopreservation techniques on the development of human pre-implantation embryos that underwent blastomere biopsy and blastocoel drainage prior to cryopreservation. DESIGN: Retrospective clinical study. PATIENT(S): Women who requested cryotransfer of supernumerary blastocysts were analyzed by FISH. RESULTS: The main outcome measures were post-thaw survival (SR), pregnancy (PR), and implantation (IR). The SR of slowly frozen blastocysts was 83% compared to 97% for vitrified blastocysts. In 160 cases where biopsied embryos were cryotransferred, the results for slowly frozen versus vitrified blastocysts were: SR (71% vs. 95%), PR (23% vs. 37%), and IR (26% vs. 36%, P < 0.05), respectively. CONCLUSION: The results revealed that vitrified blastocysts provided higher SR, PR and IR as compared to slowly frozen counterparts.
PURPOSE: Cryopreservation of blastocysts, especially those subjected to the trauma due to blastomere biopsy for the purposes of pre-implantation genetic screening (PGS), requires significant optimization. Laboratory and clinical outcomes were compared to determine the effect of two different cryopreservation techniques on the development of human pre-implantation embryos that underwent blastomere biopsy and blastocoel drainage prior to cryopreservation. DESIGN: Retrospective clinical study. PATIENT(S): Women who requested cryotransfer of supernumerary blastocysts were analyzed by FISH. RESULTS: The main outcome measures were post-thaw survival (SR), pregnancy (PR), and implantation (IR). The SR of slowly frozen blastocysts was 83% compared to 97% for vitrified blastocysts. In 160 cases where biopsied embryos were cryotransferred, the results for slowly frozen versus vitrified blastocysts were: SR (71% vs. 95%), PR (23% vs. 37%), and IR (26% vs. 36%, P < 0.05), respectively. CONCLUSION: The results revealed that vitrified blastocysts provided higher SR, PR and IR as compared to slowly frozen counterparts.
Authors: Pierre Vanderzwalmen; G Bertin; Ch Debauche; V Standaert; E van Roosendaal; M Vandervorst; N Bollen; H Zech; T Mukaida; K Takahashi; R Schoysman Journal: Hum Reprod Date: 2002-03 Impact factor: 6.918