It should be borne in mind that at the moment of biopsy, an embryo is at an early onset of development and it’s cells are totipotent stem cells, mean they can be differentiated in any kind of cells in the human body. That’s why, removal of one or several cells of the embryo will have no impact on his future development.
It should not be forgotten that PGD is used for genetic analysis of only one or several embryos` cells. Hence, the reliability of the result, although high, does not constitute 100%. A sufficient influence on the result has mosaicism – a phenomenon, when some cells of the embryo can be carriers of the genetic information, which is differ from other cells.
There are genetic changes, which are incompatible with life and in case of embryotransfer they can lead to implantation disruption or termination of pregnancy. But, there are other abnormalities, which may lead to childbirth with developmental disorders.
❕ Advantages of PGD
🔹 Exclusion of embryotransfer of aneuploid embryos, meaning embryos with genomic and chromosomal abnormalities.
🔹 Increases the frequency of implantation.
🔹 Increases the frequency of pregnancy.
🔹 Low rate of abortions.
🔹 The risk of giving birth to children with chromosomal abnormalities is reduced.
❗️ PGD disadvantages
🔺 Involves manipulations with embryos. During the biopsy, the embryo is located outside of incubator, what can have an influence on his quality. Rarely, but it can happen that the embryo can die during or after the biopsy.
🔺 Cancellation of embryotransfer due to the reason that all embryos might be aneuploidy. It is worth remembering that there are genetic changes with the slight symptoms or those, which are not dangerous for life. Also, we should take a notice about possible mosaicism, described earlier.