【作者】 张艳；

【导师】 邵小光；

【作者基本信息】 大连医科大学 ， 妇产科学， 2006， 硕士

【摘要】 背景:在体外受精(in vitro fertilization,IVF)或显微受精(intracytoplasmic sperm injection,ICSI)治疗时,取出的卵经受精后除当月周期胚胎移植外,还有剩余胚胎,如将这部分胚胎冷冻储存待以后需要时用,可以提高一次取卵的总妊娠率,节约患者的费用。因此随着辅助生育技术(assisted reproductive technology,ART)的进步,胚胎冷冻技术已经成为其发展不可分割的一部分。但是较新鲜胚胎移植而言冻融胚胎的妊娠率仍较低[1],尽管冷冻过程中产生的冷冻损伤对冻融胚胎的存活率和妊娠率的影响已经成为共识,但具体原因仍在研究中。有学者认为冷冻胚胎存在个体差异,发育潜能高的胚胎耐受冷冻过程,解冻后存活率、妊娠率不受影响,发育潜能低的胚胎则相反,解冻后存活率、妊娠率大大降低;还有学者认为冷冻损伤和冷冻技术无关,而是和冷冻过程本身有关,只要冷冻过程中产生冰晶即冷冻损伤,胚胎的存活率和种植率就会受到影响。目的:通过鼠胚模拟人类胚胎冷冻过程,以研究冷冻损伤对胚胎发育的影响。首先对比4细胞胚和8细胞胚在冷冻过程中损伤细胞数,分析冷冻损伤程度对胚胎继续发育能力的影响,然后比较新鲜鼠胚和冷冻鼠胚(包括无冷冻损伤和≤50%冷冻损伤)解冻后发育至囊胚的能力及形成扩张囊胚细胞数是否存在差异,进一步研究冷冻损伤导致胚胎发育潜能低下的原因。方法:于hCG注射后60小时收集的4细胞鼠胚为组1,68小时收集的8细胞鼠胚为组2,挑选组1和组2的Ⅱ级及其以上的鼠胚随机分为实验组和对照组,实验组为将收集到的4细胞胚或8细胞胚进行冷冻处理,解冻后按冷冻损伤程度分为无冷冻损伤组(组a)和≤50%更多还原

【Abstract】 Background Embryo cryopreservation is a well estabilished technique in most in-vitro fertilization embryo transfer(IVF-ET)clinics. It allows for storage and later transfer of supernumerary embryos obtained from IVF treatment. It can indeed achieve the high cumulative pregnancy rates and decrease the expenses of the patients. But compared with the fresh embryos,the implatation rates of cryopreservation embryo is yet low. And it is well-recognized that the cryodamage influence the embryo’s survival rates and pregnancy rates , the concrete causes have been researching. Some scholars think that it is not all frozen embyos having the properties to persist with the ultralow temperature,the better the embryos further develop, the stronger their resistant abilities are,so the survival rates and the pregnancy rates will high, vice versa. Others consider that the cryodamage has nothing to do with the cryopreservation per se,but with the cell lysis during the frozen-thawed. If the cryodamage exists,the survival rates and the implantation rates will be decreased.Objective The present study firstly examines the influence of blastomeres lost after thawing on subsequent preimplantation development in vitro by means of the mouse 4-cell and 8-cell embryos. Then compares with the development between the fresh and thawed embryos(including fully intact and≤50% patially intact embryos). At last,the total cell number of the expanded blastocysts are observed.Method The 4-cell mouse embryos(group 1) after 60 hours of injecting the HCG and 8-cell ones(group 2) after 68 hours with no more than 50% anucleate fragment are further divided into the test group and the control group. The test group,is the frozen group including the fully intact更多还原