Infertility and IVF Unit, Department of Obstetrics and Gynecology, Chaim Sheba Medical Center (Tel Hashomer), Ramat Gan, and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
The Tarnesby-Tarnowski Chair for Family Planning and Fertility Regulation, at the Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.
Hum Reprod. 2021 Apr 20;36(5):1186-1190. doi: 10.1093/humrep/deab042.
Human embryos utilise an array of processes to eliminate the very high prevalence of aneuploid cells in early embryo stages. Human embryo self-correction was recently demonstrated by their ability to eliminate/expel abnormal blastomeres as cell debris/fragments. A whole genome amplification study has demonstrated that 63.6% of blastocysts expelled cell debris with abnormal chromosomal rearrangements. Moreover, 55.5% of euploid blastocysts expel aneuploid debris, strongly suggesting that the primary source of cell free DNA in culture media is expelled aneuploid blastomeres and/or their fragments. Such a substantial ability to self-correct downstream from the blastocyststage, therefore, renders any chromosomal diagnosis at the blastocyststage potentially useless, and this, unfortunately, also must particularly include non-invasive PGT-A based on cell-free DNA in spent medium. High rates of false-positive diagnoses of human embryos often lead to non-use and/or disposal of embryos with entirely normal pregnancy potential. Before adopting yet another round of unvalidated PGT-A as a routine adjunct to IVF, we here present facts that deserve to be considered.
人类胚胎利用一系列过程来消除早期胚胎阶段非常高的非整倍体细胞发生率。人类胚胎自我纠正能力最近通过其消除/排出异常卵裂球作为细胞碎片/片段的能力得到证实。一项全基因组扩增研究表明,63.6%的囊胚排出具有异常染色体重排的细胞碎片。此外,55.5%的整倍体囊胚排出非整倍体碎片,强烈表明培养物中无细胞游离 DNA 的主要来源是排出的非整倍体卵裂球及其片段。因此,囊胚阶段之后这种强大的自我纠正能力使得囊胚阶段的任何染色体诊断都可能变得毫无用处,不幸的是,这也必须特别包括基于培养物中无细胞游离 DNA 的非侵入性 PGT-A。人类胚胎的高假阳性诊断率常常导致具有完全正常妊娠潜力的胚胎被废弃和/或处理。在采用另一轮未经证实的 PGT-A 作为 IVF 的常规辅助手段之前,我们在此提出值得考虑的事实。