Kyono ART Clinic Sendai, 1-1-1 3F, Honcho, Aobaku, Sendai, Miyagi, 980-0014, Japan.
Kyono ART Clinic Takanawa, Takanawa Court 5F, 3-13-1, Takanawa Tokyo, Minatoku, 108-0074, Japan.
J Assist Reprod Genet. 2024 Jun;41(6):1589-1596. doi: 10.1007/s10815-024-03114-9. Epub 2024 Apr 13.
Are human embryos arising from two plus one small pronucleated zygotes, called 2.1 pronuclei (PN), clinically useful?
In a retrospective embryo cohort study and prospective experimental study, a total of 287 cycles in which at least one 2.1PN was identified in the fertilization check were included. Embryonic development and clinical outcome were compared for the 1395 2PN zygotes and 304 2.1PN zygotes that were siblings. All embryos were individually cultured in time-lapse systems. Twenty-five 2.1PN-derived blastocysts, donated for research, were used in focused single-nucleotide variant ploidy analysis to identify the distribution pattern of heterozygosity.
The average diameter of PN was 24.9 ± 2.4 µm for large PN and 10.2 ± 2.4 µm for small PN; 79.9% of small PN was derived from female pronuclei. Blastocyst formation rate and good-quality blastocyst rate were significantly lower with 2.1PN embryos than with 2PN embryos (40.0% vs. 57.7%, 21.4% vs. 33.5%, respectively). A total of 13 embryos derived from 2.1PN were transferred, and three healthy babies were born. In ploidy constitutions of trophectoderm (TE), 2.1PN-derived blastocyst TE was shown to be mostly diploid (95.8%, 23/24), and only one blastocyst showed triploid.
It was suggested that 2.1PN embryos have lower embryonic developmental potential than 2PN embryos, but most of the 2.1PN were diploid, indicating that they are likely to be clinically usable. It is recommended to perform embryo transfer following a combination of PGT-A and ploidy analysis.
由两个加一个小原核受精卵（称为 2.1 原核）产生的人类胚胎在临床上是否有用？
在回顾性胚胎队列研究和前瞻性实验研究中，共纳入了 287 个受精检查中至少发现一个 2.1PN 的周期。比较了 1395 个 2PN 受精卵和 304 个 2.1PN 受精卵的胚胎发育和临床结局。所有胚胎均在延时系统中单独培养。使用 25 个用于研究的 2.1PN 衍生囊胚进行了聚焦单核苷酸变异倍性分析，以确定杂合性分布模式。
大原核 PN 的平均直径为 24.9 ± 2.4 µm，小原核 PN 的平均直径为 10.2 ± 2.4 µm；小原核 PN 中有 79.9%来自女性原核。与 2PN 胚胎相比，2.1PN 胚胎的囊胚形成率和优质囊胚率显著降低（分别为 40.0%比 57.7%，21.4%比 33.5%）。共有 13 个胚胎来源于 2.1PN，并诞生了 3 个健康婴儿。在滋养外胚层（TE）的倍性构成中，2.1PN 衍生的囊胚 TE 主要是二倍体（95.8%，23/24），仅一个囊胚显示三倍体。
提示 2.1PN 胚胎的胚胎发育潜能低于 2PN 胚胎，但大多数 2.1PN 为二倍体，表明其可能具有临床应用价值。建议在进行 PGT-A 和倍性分析相结合的情况下进行胚胎移植。
