Embryo response to aneuploidy through self-correction mechanism: a literature review

Meiotic and mitotic errors often lead to aneuploidy and mosaicism. In this context, the self-correction mechanism enables the embryo to preferentially retain and preserve euploid cells through processes such as apoptosis, necrosis, or marginalization. This mechanism is thought to minimize the chance of genetic abnormalities during cell development. A literature search for articles written in English from January 2013 to October 2023 was conducted on PubMed, EBSCO, and Scopus, using the keywords “self-correction,” “self-repair,” “aneuploidy,” “mosaicism,” and “embryo.” A total of 308 articles were collected, out of which 5 retrospective and 1 prospective study were selected based on inclusion criteria. Investigations showed that embryos remove chromosomally abnormal cells, supporting the self-correction mechanism. aCGH has been used in 4 studies to demonstrate the presence of self-correction in mosaic embryos. Furthermore, a higher relative viability of polyploidies than complex aneuploidies was observed, suggesting early discrimination against complex aneuploidy, particularly those arising from mitotic origins. However, there are doubts about the reliability of preimplantation genetic testing for aneuploidy at the blastocyst stage, as it may lead to a high rate of false positives and the discarding of "good" embryos. Studies showed a self-correction mechanism in human embryos through the ability to expel abnormal cells. Further investigation is needed to elucidate the underlying mechanisms and determine optimal strategies for preimplantation genetic testing to fully understand and optimize the use of self-correction mechanisms in embryo assessment and selection.