PGS and ‘Mosaic’ Embryos

Monica54321 · May 2016

I just read an interesting article in the NY Times about PGS and ‘Mosaic’ embryos (article here). I wonder if we (the collective IVF community) are not using a significant number of embryos that are deemed abnormal by PGS but would 'self-correct' and develop into 'normal' babies. See quote from the article below...

As an embryo rapidly divides after fertilization, mistakes in cell division sometimes produce abnormal cell lines. If those cells die off and the embryo manages to self-correct, or if the abnormal cells wind up segregated in the placenta, the embryo may develop into a normal baby.
But if abnormal cells proliferate in the embryo, it will probably fail to implant, result in a miscarriage or, more rarely, the birth of a child with serious defects.

Seems like there are definite cases PGS would be very useful, such as screening for inherited genetic diseases that are known to run in your family. Maybe it's being overused by couples who are not at a high risk for inherited genetic diseases, resulting in an increase in 'false positives' and potentially viable embryos being discarded unnecessarily. Soooo much more research is needed - BUT I was interested in discussing this with other people who are interested & care about these topics!

Did you do (or are planning to do) PGS testing or not? Why? What factors influenced your decision? Does new information like this potentially impact your decision?

vssbrm · May 2016

I too read a similar article and posted it in the April/May IVF board. It really made me think, as we did a study that included PGS testing. We do not yet know the results from the testing, but either way we will be keeping all of our remaining embryos frozen for future use either way.

Knottie1456036854 · May 2016

Small personal pet peeve here.....

PGS testing is looking for normal chromosomes
PGD testing is looking for a specific single gene disorder--like cystic fibrosis, dwarfism, or in my case a BRCA mutation.

........rant complete.....

The mosaic thought is pretty interesting. I'm sure there are some false positives because of that, but I'm not sure there is any way around it. They are biopsying something so small, they can only take that single cell and not a whole bunch to be totally sure. That's why they told us that our embryo, which was found to be normal in PGS, still has a small chance of having a chromosome problem. The cell they looked at was normal, but always a tiny possibility of mosaic issues. I wonder how common those are, though (mosaic/chimera).

We did both PGS and PGD testing, and I wouldn't do it any other way. If we are able to get some eggs from my sister, we will spend the ~$9k to have them both done again. Our genetics company reports a 98% accuracy with their results. Knowing that a 35 year old woman will have 1/2 of her embryos have a chromosome issue makes this a really easy decision for us.

Monica54321 · May 2016

@Knottie1456036854 - Thanks for clarifying the difference between PGS & PGD. I really enjoy learning as much as possible about these topics and I love having other people who feel the same to discuss with!

dragonfaerie · May 2016

We chose to do PGS testing just so we could have a little bit more peace of mind about transferring an embryo that is more likely to go to term. Our RE showed us a video about an embryo dividing and such from day one on. On day 3, there was an abnormality (which probably would have been picked up by a biopsy/PGS and deemed "abnormal,) and then the embryo actually "spit" those cells out by day 5 and was "normal." That's why my RE chooses to do day 5 biopsies and transfers, because so many issues that are there early can self-correct by day 5 or 6.
It's very hard to discern what is right and necessary, especially in IVF where are there seem to be so many little decisions you never thought you'd have to worry about. My DH and I would never have done an amniocentesis, but the decision to do PGS was almost easy for us because we just want to bring a baby home. But we chose to not look for those extra things (like you would for PGD) because we don't know of anything in the family and decided to let God have that one. But it is truly different for everyone, and I respect everyone's decision to do extra testing, no testing, or to decide that IVF is not right for them at all.

cmm012 · May 2016

I think this is a very interesting topic. @dragonfaerie Do you have the name or a link to that video? My clinic also does day 5 biopsies because they are safer for the embryo. I'm doing PGS testing to maximize my changes of a healthy pregnancy with the first transfer. I have quick growing uterine fibroids, and I'm trying to have at least one baby without another major surgery. Based on my age, about 1/2 of my embryos should be normal and 1/2 abnormal.

freudianmamma · May 2016

We just had our IVF consult on Wednesday and our RE said we "don't need" to do PGS testing at this point. When I asked him "why?" he said that because of my age and because at this point, he suspects that my endometriosis scarring is what is causing the problems we are having conceiving, he does not think we need it. I am thinking he probably takes into account that we have to pay out of pocket for this when he is talking to us about it.

I am not sure if I am confusing two things here so correct me if I am wrong but I heard on the "Beat Infertility" podcast that "lower quality" embryos often are used by couples in IVF and go on to achieve healthy pregnancies.

dragonfaerie · May 2016

@cmm012 I haven't found a specific link, but if you look for Conceptions Reproductive Associates on Facebook, one of their videos shows the right one I think.

radmom27 · May 2016

I've read this article and have done a lot of thought and personal reflection regarding PGS. We have not done PGS testing thus far and are on our 3rd IVF cycle. I have low ovarian reserve and frankly I feel that there just aren't ever enough embryos to use/test. Due to my age, I know that only 10% of my eggs are normal at this point...if I produce 10 eggs, only one of those is likely chromosomally fit. I've only had 4 ever make it through to day 5 and although it may be nice for my personal sanity to only transfer a PGS normal embryo, I suspect that I often never have one (or haven't so far). I'd rather put the money that I would use to do PGS testing into future cycles and keep going playing a numbers game hoping that eventually I'll find a "good egg." I also worry that I would inadvertantly discard normal embryos...ones that I can't spare to lose at this point.

Finally, I plan on doing cell free genetic testing once pregnant (G-D willing) and any other testing to know about chromosomal issues, but still know that there are 10,000 other issues that can occur aside from chromosomal stuff.

I do understand why others do PGS testing and think it's a really personal decision for each couple with both risks and many benefits. If I had 15 embryos at a time to choose from, I would probably feel differently and want to not go through many unnecessary transfers.

I really enjoy hearing everyone's thoughts on this issue!

Monica54321 · May 2016

radmom27 - Thanks for sharing your perspective!

We have just started looking into IVF (currently doing IUIs) and understanding all of the options / decisions that have to be made. From what I can tell so far, our clinic only recommends PGS if you have an elevated risk for chromosomal abnormalities, which I don't believe we fall into that category, so I'm anticipating we will not be doing PGS, if we end up moving on to IVF.

caseyw8784 · May 2016

We are doing PGD due to a single gene disorder that has a 50% chance of being passed down. I guess we are also doing PGS since my doctor said that they would "screen for all the other common chromosomal issues, too."

My clinic also only does 5/6 day biopsies as well, so I'm assuming that some of the other "abnormal" embryos will have been "weeded out" by then anyways.

We are lucky that my insurance is covering the costs of this extra testing...

2legbaby · May 2016

When I mentioned the info on this "self correction" of embryos, my RE indicated this applied to day 3 embryo biopsies when there are very few cells, she indicated that day 5 embryos that test normal are likely to stay normal as there are already many cells.

Want a personalized experience?

PGS and ‘Mosaic’ Embryos

Re: PGS and ‘Mosaic’ Embryos

Choose Another Board

Search Boards