部分經PGD檢查正常之囊胚仍無法著床懷孕，
原因可能在於其染色體有目前PGD無法有效偵測之染色體異常(mosaicism, subchromosomal imbalances, segmental imbalances, balanced translocation)

Fertil Steril. 2016 Nov 2. pii: S0015-0282(16)62870-4. doi: 10.1016/j.fertnstert.2016.09.039. [Epub ahead of print]

Detection of segmental aneuploidy and mosaicism in the human preimplantation embryo: technical considerations and limitations.

Treff NR1, Franasiak JM2.

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Abstract

Whole-chromosome aneuploidy screening has become a common practice to improve outcomes and decrease embryonic transfer order in patients undergoing treatment for infertility through in vitro fertilization. Despite implementation of this powerful technology, a significant percentage of euploid embryos fail to result in successful deliveries. As technology has evolved, detection of subchromosomal imbalances and embryonic mosaicism has become possible, and these serve as potential explanations for euploid embryo transfer failures. Cases involving a parent with a balanced translocation provide a unique opportunity to characterize the capabilities and limitations of detecting segmental imbalances with a variety chromosome screening platforms. Adaptation of these methods to de novo imbalances now represent an ongoing challenge in the field of preimplantation genetic screening as additional factors including mosaicism, clinical predictive value, and distinguishing true imbalances from technical artifacts must be more carefully considered.