Objective To evaluate the survival r ate of human morula embryo freezing and themorphologic al alterations during freezing,during and after thawing,and their applications in embryo selection.Design Retrospec tive obse...Objective To evaluate the survival r ate of human morula embryo freezing and themorphologic al alterations during freezing,during and after thawing,and their applications in embryo selection.Design Retrospec tive observational study.Setting Private infertility clinic.Patient (s)Con-secutive patients under age 39undergoing frozen morula embryo transfers from December 1999to May 2003.In-tervention(s)Embryo freezing was performed at the morula stage.Embryo thaw and post-thaw ETs were conducted on the same day,which is equivalent to a day 4ET.Main outcome measure(s)Morphological alterations during freezing and thawing and after thawi ng.Post-thaw embryo survival rates,transferable rates,pregnancy rates,and implantation rates.Result(s)Morula embryos showed re-versed morphological alterations d uring the freezing pro-cess;these alterations were recovered during thawing or shortly after the thawing.Post-thaw survival rates showed no significant difference between a ny of the morula sub-stages.However,embryos scored as g rade 3,which rep-resented good quality,had signific antly higher post-thaw-survival and transferable rates than grade 2and 1em-bryos.Patients who received at least one grade 3embryo had significantly higher pregnancy rates,implantation rates,and ongoing /live birth rates than other groups.Conclusion(s)An acceptable survival rate can be ac hieved after cryopreservation of human morula embryos,and morphological alterations that occur during and shortly af-ter an embryo thaw can be a feasible in dex for determining viable embryos.展开更多
文摘Objective To evaluate the survival r ate of human morula embryo freezing and themorphologic al alterations during freezing,during and after thawing,and their applications in embryo selection.Design Retrospec tive observational study.Setting Private infertility clinic.Patient (s)Con-secutive patients under age 39undergoing frozen morula embryo transfers from December 1999to May 2003.In-tervention(s)Embryo freezing was performed at the morula stage.Embryo thaw and post-thaw ETs were conducted on the same day,which is equivalent to a day 4ET.Main outcome measure(s)Morphological alterations during freezing and thawing and after thawi ng.Post-thaw embryo survival rates,transferable rates,pregnancy rates,and implantation rates.Result(s)Morula embryos showed re-versed morphological alterations d uring the freezing pro-cess;these alterations were recovered during thawing or shortly after the thawing.Post-thaw survival rates showed no significant difference between a ny of the morula sub-stages.However,embryos scored as g rade 3,which rep-resented good quality,had signific antly higher post-thaw-survival and transferable rates than grade 2and 1em-bryos.Patients who received at least one grade 3embryo had significantly higher pregnancy rates,implantation rates,and ongoing /live birth rates than other groups.Conclusion(s)An acceptable survival rate can be ac hieved after cryopreservation of human morula embryos,and morphological alterations that occur during and shortly af-ter an embryo thaw can be a feasible in dex for determining viable embryos.
