Freeze-all,for whom,when, and how

Background: The ‘freeze-all’ practice refers to the cryopreservation of all mature oocytes or viable embryos after ovarian stimulation. The development of the vitrification technique has been crucial to make this approach a reality, since it increases the post-thaw survival rates and permits comparable implantation rates with fresh embryos. Nonetheless, as implantation probabilities are comparable to fresh embryo transfer in normo-responder patients, the freeze- all strategy has demonstrated no benefits overall.Method: Narrative review in which we give an overview of this approach, discuss recent advances in the field, as well as for whom, when and how it is recommended to emply the freeze-all technique.Results: However, there is some clinical evidence that shows its feasibility. Thus, it has been demonstrated that elevation of progesterone at the end of ovarian stimulation decreases the implantation rates after the transfer of day 6 blastocysts in fresh and some uterine pathologies; freeze-all is also the preferred option for patients undergoing pre-implantation genetic testing, since there is an improvement of the results and it allows for inclusion of all blastocysts of the cohort. In high responders, the freeze-all strategy optimizes the response whilst also minimizing the risk of ovarian hyperstimulation syndrome.Conclusion: Due to the different cases that a reproductive expert might encounter, it is essential to highlight benefits and drawbacks of this practice.     

新鲜周期全胚冷冻策略不影响体外受精-胚胎移植妊娠及产科结局:≤35岁患者的疗效分析

目的 比较新鲜周期行全胚冻存年轻患者和新鲜胚胎移植的临床妊娠结局及新生儿的产科结局,评价该策略的安全性及临床应用价值.方法 回顾性分析2011年1月~2015年12月在本中心进行体外受精-胚胎移植助孕治疗的卵巢功能正常的年龄≤35岁患者共2091个周期.促排卵治疗后全部胚胎冷冻,其后行第一周期冷冻复苏移植术的年轻患者796例为研究组,同期促排卵治疗后立即行新鲜周期移植的年轻患者1295例为对照组.分析比较两组间临床妊娠结局及分娩结局.结果 两组患者平均不孕年限无统计学差异(P>0.05),平均年龄全胚冷冻组低于新鲜周期移植组(29.5岁vs 30.2岁)有统计学差异(P<0.05).两组患者促排卵天数和移植时子宫内膜厚度无统计学差异(P>0.05),全胚冷冻组促排卵总促性腺激素剂量较新鲜移植组低(P<0.05),取卵前雌激素水平全胚组为12973 pmol/L,明显高于新鲜移植组8673 pmol/L,平均获卵数全胚组是新鲜组的1.5倍,差异均有显著性(P<0.05).两组患者临床妊娠率及活产率均无统计学差异(P>0.05),全胚冷冻组无卵巢过度刺激综合征发生,而新鲜移植组有20例发生中、重度卵巢过度刺激,差异有显著性(P=0.000).两组患者的分娩孕周及新生儿平均体质量均无统计学差异(P>0.05).结论 新鲜周期治疗中出现中、重度卵巢过度刺激综合征倾向取消新鲜周期移植而进行全胚冻存,择期行解冻移植,可获得满意的临床妊娠结局及产科结局,是预防晚发性卵巢过度刺激综合征的一种理想方法.     

Use of a new set of key performance indicators for evaluating the performance of an in vitro fertilization laboratory in which blastocyst culture and the freeze-all strategy are the primary treatment in patients with in vitro fertilization

ObjectiveTo evaluate the performance of an in vitro fertilization (IVF) laboratory using a new set of key performance indicators (KPIs) when the main treatment of IVF patients had been changed.MethodsPatients who underwent fresh embryo transfer and the freeze-all strategy in August, September, and October 2017 were retrospectively studied to evaluate the performance of an IVF laboratory in September when implantation rate of fresh embryo transfer decreased. KPIs associated with blastocyst culture and the first frozen embryo transfer (FET) cycle in patients with the freeze-all strategy were compared over 3 months.ResultsDay 5 usable blastocyst and good quality blastocyst rates, and day 3 usable/good quality embryo rates were not different among the three periods. The implantation rate and KPIs associated with morphological changes in warmed blastocysts in the first FET cycle in patients with the freeze-all strategy were also not different among the periods.ConclusionsKPIs associated with embryo quality, blastocyst culture, and the pregnancy outcome of the first FET cycle in patients with the freeze-all strategy suggested that performance was unaffected in our IVF laboratory in September. These KPIs might be useful for internal quality control analysis of IVF laboratories.     

长方案全胚胎冷冻保存后首次冻融胚胎移植时机研究

目的探讨体外受精-胚胎移植(IVF-ET)患者采用长方案行超排卵后全胚冷冻,首次冻融胚胎移植时机。方法选择青海省人民医院生殖中心171例IVF-ET患者,均采用促性腺激素释放激素激动剂长方案行控制性超排卵,取卵后行全胚冷冻,根据胚胎冷冻日到冻融胚胎移植日的间隔时间分为两组,分别为间隔短(≤69 d)组80例,间隔长(>69 d)组91例,比较两组患者获卵率、受精率、卵裂率、获胚胎数、优胚率、ET优胚胎率、临床妊娠率。结果两组患者年龄、基础内分泌、不孕原因、不孕年限、BMI、子宫内膜准备方案、胚胎种类及获卵数均无明显差异。间隔短(≤69 d)组患者HCG日雌二醇(E2)水平低于间隔长(>69 d)组患者,差异有统计学意义。间隔短(≤69 d)组患者卵裂率、优胚数、临床妊娠率均高于间隔长(>69 d)组,差异有统计学意义。结论促性腺激素释放激素激动剂长方案患者,首次行经后即可复诊行冻融胚胎移植准备。     

取卵数≥15个行冻胚移植和新鲜周期移植的累积活产率比较

目的：比较首次取卵数≥15个的患者行全胚冷冻和新鲜周期移植的累积活产率(cumulative live birth rates， CLBR)及卵巢过度刺激综合征(ovarian hyperstimulation syndrome，OHSS)的发生率，评价全胚冷冻方案的临床应用价 值。方法：回顾性分析首次行体外受精或单精子卵胞浆内注射治疗且获卵数≥15个的2 842例患者的临床资料，比较 全胚冷冻(1 095例)和新鲜周期胚胎移植(1 747例)两组间的一般资料、临床基线特征、CLBR及OHSS发生率。结果： 对两组患者进行倾向性评分匹配后的患者数均为598例，其年龄、不孕因素、体重指数、基础卵泡刺激素、促性腺激 素使用天数及总剂量差异无统计学意义(均P>0.05)；全胚冷冻组的CLBR随获卵数增加而增高(P>0.05)，且全胚冷冻组 获卵数高于新鲜周期移植组(P<0.001)；一个完整周期后全胚冷冻组CLBR与新鲜周期移植组比较，差异无统计学意义 (P>0.05)，但第一移植周期后全胚冷冻组CLBR高于新鲜周期移植组(P<0.05)；全胚冷冻组中无OHSS发生，新鲜周期 移植组有7例发生中度OHSS，两组比较差异有统计学意义(P<0.05)。结论：首次取卵获卵数≥15个且有OHSS倾向的 患者行全胚冷冻可预防OHSS的发生，获得比新鲜周期移植高的CLBR。