染色體鑲嵌異常會下降胚胎著床率

不同型態或程度之染色體鑲嵌異常(高比率或低比率鑲嵌, 單染色體或多染色體，單套或三套)造成之下降幅度也有差異

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. 2023 Mar;40(3):639-652.

 doi: 10.1007/s10815-023-02728-9. Epub 2023 Jan 25.

Clinical outcomes of subtypes of mosaic single aneuploid embryos after preimplantation genetic testing for aneuploidy

Objective: Mosaic embryos are often characterized by different numbers (single or double or ≥ 3 aneuploidies) or types of chromosomal abnormalities (monosomy or trisomy and involving whole chromosome or chromosome segments). However, due to limitations in the number of samples, the relationship between these abnormalities and clinical outcomes is often not evaluated.

Methods: This study analyzed chromosomal abnormalities and clinical outcomes in 591 aneuploid mosaic and 3071 euploid embryos from multiple retrospective cohorts as well as from the current authors' unpublished retrospective cohort.

Results: Through meta-analysis, it was found that single aneuploid mosaicism reduced implantation and clinical pregnancy rates. In addition, no significant differences were noted between mosaic trisomies and mosaic monosomies in terms of their effects on implantation and clinical pregnancy rates. All subtypes of single aneuploid mosaicism were found to reduce implantation and clinical pregnancy rates for women of over 35 years old. Furthermore, it was observed that all subtypes of single aneuploid in higher-level mosaicism reduced implantation and clinical pregnancy rates. Regarding the lower-level group, only segmental mosaicism with segmental chromosome gain reduced both of the above rates. Unexpectedly, the type of chromosome abnormality was more likely to influence miscarriage rates compared with the level of mosaicism. Indeed, monosomy aneuploid mosaic embryos increased miscarriage rates in both lower- and higher-levels mosaic ratio groups, but not other subtypes.

Conclusions: Although the mechanism for the above phenomenon remains unknown, it is recommended that attention should still be paid to the increased miscarriage rates caused by monosomy in aneuploid mosaic embryos.