The pattern of metabolism by early embryos in vitro has been linked to a range of phenotypes, including viability. However, the extent to which metabolic function of embryos is modified by specific methods used during ART has yet to be fully described. This study has sought to determine if the mode of fertilization used to create embryos affects subsequent embryo metabolism of substrates. A metabolic profile, including consumption of key substrates and the endogenous triglyceride content of individual IVF and ICSI supernumerary embryos, was assessed and compared. Embryo development and quality was also recorded. All embryos were donated at a single clinical IVF center, on Day 5, from 36 patients aged 18-38 years, The data revealed that consumption of glucose and pyruvate, and production of lactate, did not differ between embryos created by IVF or ICSI. Similarly, the mode of insemination did not impact on the triglyceride content of embryos. However, ICSI-derived embryos displayed a more active turnover of amino acids (P = 0.023), compared to IVF embryos. The specific amino acids produced in higher quantities from ICSI compared to IVF embryos were aspartate (P = 0.016), asparagine (P = 0.04), histidine (P = 0.021) and threonine (P = 0.009) while leucine consumption was significantly lower (P = 0.04). However, importantly neither individual nor collective differences in amino acid metabolism were apparent for sibling oocytes subjected to either mode of fertilization. Embryo morphology (the number of top grade embryos) and development (proportion reaching the blastocyst stage) were comparable in patients undergoing IVF and ICSI. In conclusion, the microinjection of spermatozoa into oocytes does not appear to have an impact on subsequent metabolism and viability. Observed differences in amino acid metabolism may be attributed to male factor infertility of the patients rather than the ICSI procedure per se.

中文翻译：

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体外衍生的人类胚胎的代谢特征不受受精方式的影响。

早期胚胎体外代谢模式与一系列表型有关，包括活力。然而，ART 期间使用的特定方法对胚胎代谢功能的改变程度尚未得到充分描述。这项研究试图确定用于产生胚胎的受精模式是否会影响随后的胚胎底物代谢。评估和比较了代谢概况，包括关键底物的消耗以及单个 IVF 和 ICSI 多余胚胎的内源性甘油三酯含量。还记录了胚胎发育和质量。所有胚胎均在第 5 天从单一临床 IVF 中心捐赠，来自 36 名 18-38 岁的患者。数据显示，IVF 或 ICSI 产生的胚胎之间葡萄糖和丙酮酸的消耗以及乳酸的产生没有差异。同样，授精方式也不影响胚胎的甘油三酯含量。然而，与 IVF 胚胎相比，ICSI 衍生胚胎显示出更活跃的氨基酸更新（P = 0.023）。与 IVF 胚胎相比，ICSI 产生的特定氨基酸数量较多，包括天冬氨酸 (P = 0.016)、天冬酰胺 (P = 0.04)、组氨酸 (P = 0.021) 和苏氨酸 (P = 0.009)，而亮氨酸消耗量明显较低 (P = 0.04）。然而，重要的是，对于接受这两种受精模式的兄弟卵母细胞来说，氨基酸代谢的个体差异和集体差异均不明显。接受 IVF 和 ICSI 的患者的胚胎形态（顶级胚胎的数量）和发育（达到囊胚阶段的比例）相当。总之，将精子显微注射到卵母细胞中似乎不会对随后的代谢和活力产生影响。观察到的氨基酸代谢差异可能归因于患者的男性不育因素，而不是 ICSI 程序本身。