Vitrification of Biopsied Mouse Embryos At 8-cell, Morula and Blastocyst Stages Using A Modified Vitrification Medium

Abstract

BACKGROUND: Vitrification of biopsied embryos plays an important role in preimplantation genetic diagnosis cases using CGH and array CGH METHODS which may require cryopreservation of the biopsied embryos for later transfer.OBJECTIVE(S): The objective of this study is to investigate the effect of vitrification on biopsied embryos at various stages using a modified vitrification medium.MATERIAL AND METHOD(S): The mouse embryos were biopsied and vitrified at 8-cell, morula and blastocyst stages using a modified vitrification medium with low concentration of DMSO to avoid potential toxicity. Non-biopsied mouse embryos at the same stages were vitrified as control. The vitrified embryos were thawed and analyzed by their survival rate, blastocyst formation and hatching rates.RESULT(S): At 8-cell stage, the overall survival rate of the non biopsied embryos was significantly higher than the biopsied embryos (94% versus 68%), P<0.05). The blastocyst formation rates of both groups after thawing are similar (87% versus 85%, P>0.05). At morula stage, both biopsied and non biopsied groups had similar survival rate (96% versus 92%, P>0.05). After thawing, the blastocyst formation rate of the biopsied group is comparable to that of the non biopsied group (93% versus 94%, P>0.05). At blastocyst stage, both biopsied and non biopsied embryos had similar survival rate (92% versus 91%, P>0.05). The hatching blastocyst rates in both groups are similar (86% verse 89%, P>0.05).CONCLUSION(S): The above data suggests that the survival rate and developmental potential of the biopsied mouse embryos at morula and blastocyst stages are similar to those of the non biopsied embryos using the modified vitrification medium. Moreover, vitrification of biopsied embryos at advanced stage shows better survival rate when compared to cleavage stage embryos using the modified vitrification medium.SUPPORT: Institutional funds BACKGROUND: Vitrification of biopsied embryos plays an important role in preimplantation genetic diagnosis cases using CGH and array CGH METHODS which may require cryopreservation of the biopsied embryos for later transfer. OBJECTIVE(S): The objective of this study is to investigate the effect of vitrification on biopsied embryos at various stages using a modified vitrification medium. MATERIAL AND METHOD(S): The mouse embryos were biopsied and vitrified at 8-cell, morula and blastocyst stages using a modified vitrification medium with low concentration of DMSO to avoid potential toxicity. Non-biopsied mouse embryos at the same stages were vitrified as control. The vitrified embryos were thawed and analyzed by their survival rate, blastocyst formation and hatching rates. RESULT(S): At 8-cell stage, the overall survival rate of the non biopsied embryos was significantly higher than the biopsied embryos (94% versus 68%), P<0.05). The blastocyst formation rates of both groups after thawing are similar (87% versus 85%, P>0.05). At morula stage, both biopsied and non biopsied groups had similar survival rate (96% versus 92%, P>0.05). After thawing, the blastocyst formation rate of the biopsied group is comparable to that of the non biopsied group (93% versus 94%, P>0.05). At blastocyst stage, both biopsied and non biopsied embryos had similar survival rate (92% versus 91%, P>0.05). The hatching blastocyst rates in both groups are similar (86% verse 89%, P>0.05). CONCLUSION(S): The above data suggests that the survival rate and developmental potential of the biopsied mouse embryos at morula and blastocyst stages are similar to those of the non biopsied embryos using the modified vitrification medium. Moreover, vitrification of biopsied embryos at advanced stage shows better survival rate when compared to cleavage stage embryos using the modified vitrification medium. SUPPORT: Institutional funds