Macas E, Imthurn B, Borsos M, Rosselli M, Maurer-Major E, Keller P J
Department of Gynecology and Obstetrics, Endocrinology Clinic, University Hospital Zurich, Switzerland.
Fertil Steril. 1998 Apr;69(4):630-5. doi: 10.1016/s0015-0282(98)00021-1.
To evaluate the effects of cryopreservation on the survival, cleavage, and morphology of embryos and on the implantation and embryonic loss rates of human zygotes obtained after ICSI compared with frozen-thawed zygotes obtained after traditional IVF. A further objective was to evaluate the same parameters in nonfrozen sibling ICSI and IVF zygotes and to compare them with corresponding frozen-thawed zygotes.
Open, retrospective, comparative study.
University-associated assisted reproductive program.
PATIENT(S): Couples with severe male factor infertility and couples undergoing IVF during the same period.
INTERVENTION(S): A cohort of 408 ICSI zygotes and 299 IVF zygotes was frozen in 1,2 propanediol and sucrose using a slow-freezing protocol. Both groups of zygotes were frozen at approximately the same time after microassisted or conventional insemination. One hundred and eighty-seven ICSI and 110 IVF frozen zygotes were rapidly thawed during 44 ICSI cycles and 24 IVF cycles. Zygotes that appeared to have survived were cultured for 24 hours, and most of these embryos that were morphologically normal were transferred into patients.
MAIN OUTCOME MEASURE(S): Survival rate (morphologically intact after thawing), cleavage rate and morphology of embryos, implantation rate, and the incidence of embryonic losses.
RESULT(S): Except for survival rates, for which both ICSI and IVF frozen-thawed zygotes showed similar and relatively high values (87.7% and 89.1%), the outcomes of other parameters evaluated were significantly different. Thus, from a total of 128 ICSI and 68 IVF embryos transferred, 14 (10.9%) and 17 (25.0%) implanted in 44 ICSI and 24 IVF frozen-thawed cycles, respectively. This difference in implantation corresponded with the rate of cleavage and morphology of the replaced embryos; the embryos that developed from frozen-thawed IVF zygotes cleaved faster and were more regular compared to the frozen-thawed ICSI zygotes. The embryonic loss rate was 57.1% for cryopreserved ICSI zygotes and 11.8% for IVF zygotes. On the other hand, no difference in cleavage pattern, embryo morphology, implantation, and embryonic loss rates was found between nonfrozen sibling ICSI and IVF zygotes.
CONCLUSION(S): The zygotes arising from ICSI cycles survived cryopreservation at a rate similar to IVF zygotes, but their ability to implant and develop further was probably affected by the cryopreservation procedure. The timing of zygote freezing was considered to be the principal reason for the lower developmental potential of frozen-thawed ICSI zygotes in the present study.
评估冷冻保存对胚胎存活、分裂及形态的影响，以及对卵胞浆内单精子注射（ICSI）后获得的人类受精卵与传统体外受精（IVF）后获得的冻融受精卵的着床率和胚胎丢失率的影响。另一个目的是评估未冷冻的同胞ICSI和IVF受精卵的相同参数，并将它们与相应的冻融受精卵进行比较。
开放性、回顾性、对照研究。
大学附属辅助生殖项目。
重度男性因素不育夫妇以及同期接受IVF的夫妇。
采用慢速冷冻方案，将408个ICSI受精卵和299个IVF受精卵置于1,2 - 丙二醇和蔗糖中冷冻。两组受精卵在显微辅助或常规授精后大致相同时间进行冷冻。在44个ICSI周期和24个IVF周期中，将187个ICSI和110个IVF冷冻受精卵快速解冻。看起来存活的受精卵培养24小时，其中大多数形态正常的胚胎被移植到患者体内。
存活率（解冻后形态完整）、胚胎分裂率和形态、着床率以及胚胎丢失发生率。
除存活率外，ICSI和IVF冻融受精卵的存活率相似且相对较高（分别为87.7%和89.1%），评估的其他参数结果有显著差异。因此，在总共移植的128个ICSI胚胎和68个IVF胚胎中，分别有14个（10.9%）和17个（25.0%）在44个ICSI和24个IVF冻融周期中着床。着床的这种差异与移植胚胎的分裂率和形态相对应；与冻融ICSI受精卵发育而来的胚胎相比，冻融IVF受精卵发育而来的胚胎分裂更快且更规则。冷冻保存的ICSI受精卵的胚胎丢失率为57.1%，IVF受精卵为11.8%。另一方面，未冷冻的同胞ICSI和IVF受精卵在分裂模式、胚胎形态、着床和胚胎丢失率方面未发现差异。
ICSI周期产生的受精卵在冷冻保存后的存活率与IVF受精卵相似，但其着床和进一步发育的能力可能受到冷冻保存程序的影响。在本研究中，受精卵冷冻的时机被认为是冻融ICSI受精卵发育潜力较低的主要原因。
