IVF Centers Prof. Zech - Bregenz, Römerstrasse 2, 6900 Bregenz, Austria.
Hum Reprod. 2013 Nov;28(11):2950-7. doi: 10.1093/humrep/det361. Epub 2013 Sep 12.
Does the storage time of vitrified human blastocysts negatively impact their survival, the implantation potential of embryos or the malformation rate of babies born?
There was no evidence that storage times of up to 6 years after vitrification (VIT) had a negative impact on blastocyst survival, the implantation potential of embryos or the malformation rate of babies born.
Although several thousand children have been born after blastocyst VIT, many aspects of this technique remain to be elucidated. New applications, such as fertility preservation, lead to long storage times of vitrified gametes or embryos but it remains to be determined if these vitrified embryos are stable over time.
STUDY DESIGN, SIZE, DURATION: A retrospective study including 603 transfers was conducted between January 2009 and April 2012. Blastocysts were vitrified using a closed system.
PARTICIPANTS/MATERIALS, SETTING, METHODS: All patients underwent the transfer of aseptically vitrified/warmed blastocysts in a cryo-cycle. A total of 1077 blastocysts were transferred. Survival rates (SRs), implantation potential, birth rates and characteristics of the children born were evaluated.
We found that the storage of vitrified blastocysts in aseptic conditions neither impaired blastocyst viability (SR after warming during the first year of storage was 83.0% compared with 83.1% after 5-6 years of storage: NS) nor decreased pregnancy rates (clinical pregnancy rate after 1 year of storage was 40.0 versus 38.5% after 6 years: NS). In addition, no increase in the malformation rate over time was observed.
LIMITATIONS, REASONS FOR CAUTION: Our study only included the transfer of blastocysts which had been vitrified aseptically (i.e. using a closed system). Therefore, our results might not be applicable to 'open' VIT systems. The long-term follow-up of children born will be necessary to confirm our findings.
The results suggest that vitrified human blastocysts can be stored for long periods of time without significant negative consequences for the offspring. Therefore, the method should be of benefit to those patients who need to consider taking measures for fertility preservation.
STUDY FUNDING/COMPETING INTEREST(S): No external funding was sought for this study and the authors have no conflict of interest to declare.
玻璃化冷冻保存的人类囊胚储存时间是否会对囊胚存活率、胚胎着床潜能或新生儿畸形率产生负面影响？
在玻璃化冷冻保存后长达 6 年的时间内，储存时间并没有对囊胚存活率、胚胎着床潜能或新生儿畸形率产生负面影响。
尽管已经有几千名儿童通过囊胚玻璃化冷冻保存技术出生，但该技术的许多方面仍有待阐明。新的应用，如生育力保存，导致了更长时间的玻璃化冷冻保存配子或胚胎，但仍需要确定这些玻璃化冷冻保存的胚胎是否随着时间的推移而稳定。
研究设计、大小、持续时间：这是一项回顾性研究，纳入了 2009 年 1 月至 2012 年 4 月间进行的 603 次转移。囊胚采用封闭系统进行玻璃化冷冻保存。
参与者/材料、设置、方法：所有患者均在无菌条件下接受玻璃化冷冻/解冻的囊胚移植。共移植了 1077 个囊胚。评估了存活率（SR）、着床潜能、出生率和出生儿童的特征。
我们发现，在无菌条件下储存玻璃化冷冻保存的囊胚既不会损害囊胚的活力（储存第 1 年的解冻后 SR 为 83.0%，而储存 5-6 年后为 83.1%：无显著性差异），也不会降低妊娠率（储存 1 年后的临床妊娠率为 40.0%，而 6 年后为 38.5%：无显著性差异）。此外，随着时间的推移，畸形率并没有增加。
局限性、谨慎的原因：我们的研究仅包括了无菌玻璃化冷冻保存的囊胚的移植（即使用封闭系统）。因此，我们的结果可能不适用于“开放式”玻璃化冷冻保存系统。有必要对出生的儿童进行长期随访，以确认我们的发现。
研究结果表明，人类囊胚可以长时间储存，而不会对后代产生显著的负面影响。因此，该方法将有益于那些需要考虑采取生育力保存措施的患者。
研究资金/利益冲突：本研究没有寻求外部资金支持，作者没有利益冲突需要申报。
