Does genetic testing of embryos impact the child?

Submitted by grumble11 t3_y1rwe6 in askscience

So current genetic testing of IVF embryos is to get the egg and sperm together, make a bunch of embryos, wait a few days to see which ones grow and then to pop them open, scrape out a bunch of cells and then send them to the lab. The lab then tests those cells for any abnormalities (aneuploidy, etc) while the embryos get frozen. Once results are back the cleared embryos can be implanted one at a time until one takes.

So there has been some research on childhood cancer risk of frozen embryos and that seems to be a bit elevated relative to standard - 1.6-1.7 times.

https://journals.plos.org/plosmedicine/article?id=10.1371%2Fjournal.pmed.1004078

This is still a fairly new process and we don’t know if there are any impacts later in life from freezing, it’s an open question as frozen embryo children hit middle age. Fingers crossed.

My question was on the genetic testing side. If you have an embryo and pop it open and remove a bunch of the very first cells, then the remaining cells step up and still deliver a baby. That is established. What impacts might arise from the cell removal process though? Like if you were going to have 100 cells at that point and are now down to 90 or whatever then would that have any impacts later in life? The remaining cells need to divide more I guess. Thoughts?

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meathole t1_is0tm37 wrote

The cells are not taken from the embryo directly, they are taken from the Trophectoderm which is comprised of extra-embryonic tissue which does not become part of the fetus itself. Cells in the Trophectoderm become part of the support structure for the fetus like the placenta.

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Med_vs_Pretty_Huge t1_is10wzy wrote

Depends on the exact procedure. Blastomere biopsies are before that distinction.

EDIT: Had to edit my post because both blastomere and blastocyst biopsies happen on day 3 (blastomere in the early part of day 3, blastocyst later in day 3) but my overall point of "it depends on the exact nature of the test" is unchanged.

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Med_vs_Pretty_Huge t1_is0opxd wrote

>Like if you were going to have 100 cells at that point and are now down to 90 or whatever

They do it even earlier than that, at like the 8 cell stage when presumably it is so early in embryogenesis that there's no impact. You are right that it is still a relatively new technology but so far there has yet to be evidence that it has any impact on the fetus beyond the IVF process itself.

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