Purpose

This study evaluated the potential viability of embryos with low mosaicism level (< 50%) by comparing the clinical outcomes of single mosaic versus euploid blastocyst transfer. In addition, the live birth outcomes for various types of mosaicism with respect to abnormalities in chromosome structure and content were analyzed.

Methods

This study included patients who underwent in vitro fertilization with preimplantation genetic testing for aneuploidy (PGT-A). The PGT-A cycles performed through next-generation sequencing with single euploid or mosaic embryo transfers were included. We collected 299 frozen single embryo transfer cycles—216 single euploid and 83 mosaic—between July 2016 and July 2018. This study analyzed clinical outcomes, including fetal karyotyping by using amniocentesis, gestational age at delivery, and live birth weight after single mosaic embryo transfer.

Results

The average birth weight of infants in the euploid and mosaic blastocyst transfer groups was 3146.2 and 2997.7 g, respectively. The karyotyping results of prenatal diagnosis in all pregnant women were normal. Our study indicated that mosaic embryos can develop into euploid healthy infants with various levels or types of mosaicism. No significant difference was observed between infants from euploid and mosaic blastocyst transfers.

Conclusion

If patients have no euploid embryos, mosaic embryos can be transferred as they have potential for implantation and development into euploid healthy infants. This study is invaluable for counseling clinical results after single mosaic embryo transfers.

中文翻译：

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在非整倍体的植入前基因检测后，通过移植低镶嵌度胚胎获得健康的活产。

目的

本研究通过比较单镶嵌与整倍体囊胚移植的临床结果，评估了低镶嵌水平 (<50%) 胚胎的潜在生存能力。此外，分析了与染色体结构和内容异常相关的各种类型嵌合体的活产结果。

方法

该研究包括接受体外受精并进行非整倍体 (PGT-A) 植入前基因检测的患者。包括通过单整倍体或嵌合体胚胎移植通过下一代测序进行的 PGT-A 循环。我们在 2016 年 7 月至 2018 年 7 月期间收集了 299 个冷冻单胚胎移植周期——216 个单整倍体和 83 个嵌合体。本研究分析了临床结果，包括使用羊膜穿刺术进行的胎儿核型分析、分娩时的胎龄和单嵌合体胚胎移植后的活产体重.

结果

整倍体和嵌合囊胚移植组婴儿的平均出生体重分别为3146.2和2997.7 g。所有孕妇产前诊断的核型分析结果均正常。我们的研究表明，嵌合胚胎可以发育成具有不同程度或类型嵌合体的整倍体健康婴儿。整倍体和嵌合囊胚移植的婴儿之间没有观察到显着差异。

结论

如果患者没有整倍体胚胎，可以移植镶嵌胚胎，因为它们有可能植入和发育成整倍体健康婴儿。这项研究对于咨询单个镶嵌胚胎移植后的临床结果是非常宝贵的。