Department of Obstetrics and Gynaecology, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam.
IVFMD, My Duc Hospital and HOPE Research Center, Ho Chi Minh City, Vietnam.
Hum Reprod. 2022 Jun 30;37(7):1388-1393. doi: 10.1093/humrep/deac103.
IVF has traditionally involved transfer of fresh embryos. However, a 'freeze-all' strategy where all embryos are cryopreserved for transfer in subsequent, unstimulated cycles has emerged as an alternative approach. This is thought to eliminate the negative effects of controlled ovarian stimulation on the endometrium and reduce the risk of ovarian hyperstimulation syndrome (OHSS). There are a growing number of studies evaluating live birth rates after use of a freeze-all versus fresh embryo transfer (ET) strategy. However, results to date are inconsistent. Certainly, the benefits of a freeze-all strategy appear to be less clear cut in ovulatory women with infertility, while those with a good ovarian response (more than 10 or 15 oocytes retrieved) may be suitable candidates. Variable responses to a freeze-all strategy compared with fresh ET have also been reported depending on whether cleavage stage embryos or blastocysts were transferred. In terms of safety, the risk of OHSS appears to be lower with a freeze-all strategy. For other safety endpoints, some appear to be better when a freeze-all approach is used (e.g. rates of pregnancy loss/miscarriage, preterm delivery, low birthweight and small for gestational age) while other complications are more common (e.g. hypertensive disorders of pregnancy/pre-eclampsia, large for gestational age and high birthweight). Preliminary longer-term data suggest that a freeze-all strategy does not have a negative impact on childhood development. Other factors to consider include time to pregnancy (longer after freeze-all) and the relative cost-effectiveness of the two approaches. Available data are too inconsistent to allow a freeze-all approach to be recommended for all patients. Instead, a personalized, balanced approach should be taken based on individual patient characteristics (especially steroid hormone levels on the day of trigger) and incorporating patient preference. While a freeze-all strategy might be the right choice for some patients, freeze-all is definitely not good for all.
体外受精（IVF）传统上涉及新鲜胚胎的移植。然而，一种“全冷冻”策略，即将所有胚胎冷冻保存，以便在随后的非刺激周期中进行移植，已成为一种替代方法。这被认为可以消除控制性卵巢刺激对子宫内膜的负面影响，并降低卵巢过度刺激综合征（OHSS）的风险。越来越多的研究评估了使用全冷冻与新鲜胚胎移植（ET）策略后的活产率。然而，迄今为止的结果并不一致。当然，在排卵正常的不孕女性中，全冷冻策略的益处似乎不那么明显，而对于卵巢反应良好（获得超过 10 或 15 个卵母细胞）的女性可能是合适的候选者。与新鲜 ET 相比，全冷冻策略的反应也存在差异，这取决于移植的是卵裂期胚胎还是囊胚。就安全性而言，全冷冻策略似乎降低了 OHSS 的风险。对于其他安全性终点，一些似乎在使用全冷冻方法时更好（例如流产/流产率、早产、低出生体重和小于胎龄儿），而其他并发症更为常见（例如妊娠高血压疾病/子痫前期、大于胎龄儿和出生体重过大）。初步的长期数据表明，全冷冻策略不会对儿童发育产生负面影响。其他需要考虑的因素包括妊娠时间（全冷冻后较长）和两种方法的相对成本效益。现有的数据还不够一致，无法推荐所有患者都采用全冷冻方法。相反，应该根据个体患者的特点（尤其是触发日的类固醇激素水平），并结合患者的偏好，采取个性化、平衡的方法。虽然全冷冻策略可能是某些患者的正确选择，但全冷冻并不适合所有患者。
