体外受精胚胎冷冻储存及其移植的应用

本文的目的在于说明冷冻储存胚胎，适时解冻移植可以增加体外受精胚胎移植的妊娠成功率。第一例应用－Ｔｕｒｎｅｒ’ｓ综合征患者，丈夫无精症，在激素替代疗法下移植冻融胚胎，妊娠，于１９９５年２月６日分娩健康女婴，追踪检查生长发育良好。另外２例在超排卵刺激下获多个卵子及体外受精胚胎当月移植未获妊娠。而分别于５个月及６个月后在正常周期中移植自己的冻融胚胎，临床妊娠成功，妊娠在继续中，一例为双胞胎，三例都采用在２～８分裂球阶段冷冻。细胞内冷冻保护剂为丙二醇，细胞外保护剂为蔗糖。Ｔｅｓｔａｒｔ慢冻过程中诱发冰晶步骤很重要，可以控制溶液中的冰晶形成，避免细胞损害。

Cryopreservation of Embryos in an IVF - ET Program

The Purpose of this paper is to describe the use of cryopreservation of embryos in our IVF ET program. The first case of frozen - thawed embryo transfer was done in a Turner's syndrome patient, her husband had azoospermia. Pregnancy was achieved under hormonal replacement therapy, whose a term female baby was delivered by cesarean section on Feb. 6, 1995. Follow - up examination of the child revealed normal findings. In the other two cases of IVF-ET,many preembryos were obtained, but transfers in both cases during the stimulated cycle did not achieve pregnancy. The supernumerary embryos were cryopreserved. Transfers during the natural cycle with the frozen - thawed embryos 5 and 6 months later respectively resulted in clinical pregnancies,one twin and one singleton,as revealed by B ultrasonography. The pregnancies were on-going satisfactorily.In all three caes,the cryopreservation was done at the preembryo stage of 2 to 8 cells by the Testart's slow freezing and rapid thawing procedure with slight modifications. Propanediol was chosen as the intracellular cryoprotectant,and sucrose as the extracellular cryoprotectant. Seeding was an important step in the procedure in order to control the slow formation of ice crystals in the soultion so as to minimize damage to tile cells. The first case demonstrated that pregnancy could be achieved in couples with incurable reproductive defects, with donated embryos cryopreserved and ready for use whenever the endometrium is prepared by hormonal replacement therapy to be synchronous with the embryo development. The latter two cases illustrated that one egg retrieval may serve for many future chances of embryo transfer,and therefore increase the cumulative pregnancy success rate.