SummaryThe optimum oxygen tension for culturing mammalian embryos has been widely debated by the scientific community. While several laboratories have moved to using 5% as the value for oxygen tension, the majority of modern in vitro fertilization (IVF) laboratory programmes still use 20%. Several in vivo studies have shown the oxygen tension measured in the oviduct of mammals fluctuates between 2% and 8% and in cows and primates this values drops to <2% in the uterine milieu. In human IVF, a non-physiological level of 20% oxygen has been used in the past. However, several studies have shown that atmospheric oxygen introduces adverse effects to embryo development, not limited to numerous molecular and cellular physiology events. In addition, low oxygen tension plays a critical role in reducing the high level of detrimental reactive oxygen species within cells, influences embryonic gene expression, helps with embryo metabolism of glucose, and enhances embryo development to the blastocyst stage. Collectively, this improves embryo implantation potential. However, clinical studies have yielded contradictory results. In almost all reports, some level of improvement has been identified in embryo development or implantation, without any observed drawbacks. This review article will examine the recent literature and discusses ongoing efforts to understand the benefits that low oxygen tension can bring to mammal embryo development in vitro.

中文翻译：

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低氧浓度为 5% 的胚胎培养：简短回顾

总结 用于培养哺乳动物胚胎的最佳氧分压已被科学界广泛争论。虽然一些实验室已经开始使用 5% 作为氧分压值，但大多数现代实验室体外受精 (IVF) 实验室计划仍使用 20%。一些体内研究表明，哺乳动物输卵管中测得的氧分压在 2% 和 8% 之间波动，而在奶牛和灵长类动物中，该值在子宫环境中降至 <2%。在人类体外受精中，过去使用了非生理水平的 20% 氧气。然而，几项研究表明，大气中的氧气会对胚胎发育产生不利影响，而不仅限于许多分子和细胞生理事件。此外，低氧张力在降低细胞内有害活性氧的高水平、影响胚胎基因表达、帮助胚胎葡萄糖代谢和促进胚胎发育至囊胚阶段方面发挥着关键作用。总的来说，这提高了胚胎植入的潜力。然而，临床研究得出了相互矛盾的结果。在几乎所有的报告中，在胚胎发育或植入方面已经确定了一定程度的改进，没有任何观察到的缺点。这篇评论文章将审查最近的文献并讨论正在进行的努力以了解低氧张力可以为哺乳动物胚胎发育带来的好处体外.