Study On Blastocyst Cryopreservation And Effect Of The Frozen-thawed Process On Ultrastructure Of Human Blastocyst

Objective: Blastocyst cryopreservation is of the great importance,but there were no reports systematically by now. The objective of this study was undertaken to find a new effective and convenience method to improve the technique on blastocyst vitrification. The present study was conducted: (1) To investigate the effects of different cyroprotectants,different carriers,pretreatment methods and cryoprotective procedures on the survival and hatching rate of mouse blastocysts.(2)To compare the survival and hatching rate of human blastocyst cyropreserved with two different methods using non-transferable embryos, and to observe the ultrastructure characteristics of high-quality fresh and cyropreserved human blastocysts with different methods.Methods: (1) 90 clean ICR female and 30 clean ICR male mice were used for the experiment, Obtained mouse blastocysts were cyropreserved by conventional controled-rate freezing and vitrification with hemi-straw or dish-microdrop method,the survival and hatching rate were observed; Artificial shrinkage was induced in 65 complete expanded mouse blastocysts using Laser before vitrification in hemi-straw, after thawed, the survival and hatching rate were observed. Vitrified mouse blastocysts were transferred into surrogate mice,the pregnance were observed. (2) 67 human blastocysts were cyropreserved by vitrification with hemi-straw or by conventional controled-rate freezing, after thawed, the survival and hatching rate were...