SummaryThe aim of this study was to provide a more comprehensive understanding of 1PN intracytoplasmic sperm injection (ICSI) zygotes. To achieve this objective, we assessed whether all 1PN-derived embryos showed a similar morphokinetic pattern, and if the morphokinetic behaviour of 1PN-derived embryos was comparable with that of 2PN-derived embryos. In total, 149 1PN ICSI zygotes (study group) and 195 2PN ICSI zygotes (control group) were included in the study. Embryo development potential was evaluated in terms of blastocyst rate. Morphokinetic parameters, including the pronucleus diameter and kinetics of in vitro development, were also analyzed. Embryos derived from 1PN ICSI zygotes showed impaired development compared with 2PN-derived embryos, with blastocyst rates of 28.9% and 67.2%, respectively. The diameter of the pronucleus of 1PN zygotes was larger than that of 2PN zygotes. When compared with 2PN-derived embryos, those derived from 1PN zygotes had a visible pronucleus for a shorter time, in addition to a longer syngamy time and slower kinetic behaviour from two to nine cells. When 1PN-derived blastocysts and 2PN-derived blastocysts were compared, the developmental kinetics were similar in both groups, except for a delayed and longer duration of the compaction phase in 1PN-derived embryos. In conclusion, monopronucleated ICSI zygotes present differences in developmental capacity and morphokinetic behaviour compared with 2PN ICSI zygotes, showing particular morphokinetic parameters related to pronucleus formation. Only the 1PN ICSI-derived embryos that reached the blastocyst stage have similar morphokinetic development to blastocysts from 2PN zygotes.

中文翻译：

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直到囊胚期的单核ICSI受精卵的形态动力学和体外发育潜力

摘要本研究的目的是更全面地了解 1PN 胞浆内单精子注射 (ICSI) 受精卵。为了实现这一目标，我们评估了所有 1PN 衍生胚胎是否显示出相似的形态动力学模式，以及 1PN 衍生胚胎的形态动力学行为是否与 2PN 衍生胚胎的形态动力学行为相当。总共有 149 个 1PN ICSI 受精卵（研究组）和 195 个 2PN ICSI 受精卵（对照组）被纳入研究。根据囊胚率评估胚胎发育潜力。形态动力学参数，包括原核直径和动力学体外发展，也进行了分析。与源自 2PN 的胚胎相比，源自 1PN ICSI 受精卵的胚胎发育受损，胚泡率分别为 28.9% 和 67.2%。1PN受精卵原核直径大于2PN受精卵。与源自 2PN 的胚胎相比，源自 1PN 受精卵的胚胎具有可见的原核时间更短，此外还具有更长的结合时间和 2 到 9 个细胞的较慢动力学行为。当比较 1PN 衍生的胚泡和 2PN 衍生的胚泡时，两组的发育动力学相似，除了 1PN 衍生胚胎的压实阶段延迟和更长的持续时间。总之，与 2PN ICSI 受精卵相比，单核 ICSI 受精卵在发育能力和形态动力学行为方面存在差异，显示与原核形成相关的特定形态动力学参数。只有达到囊胚阶段的 1PN ICSI 衍生胚胎具有与来自 2PN 受精卵的囊胚相似的形态动力学发育。