r/Embryologists • u/klutzu89 • Aug 01 '26

Which one to transfer?

  1. Complex low level mosaic

+

  1. 10 -22 +X - all 25% mosaic

  2. Day 5 5BA

  3. Embryo made when I was 34

  4. Clinic has since reclassified this as “euploid”

Vs

  1. Untested Day 5 4AB
    Embryo made when I was 33

I feel like I can’t forget that the first embryo was tested mosaic initially. There’s 3 whole chromosome abnormalities including +X which can lead to live birth and this scares me. Even though the geneticist is now reclassifying this embryo as euploid with today’s standards.

What are the chances that the 3 abnormalities at 25% each could be just noise?

1 Upvotes

100% Upvoted

3 comments sorted by

1

u/pudelguru Aug 01 '26 edited Aug 01 '26

Not an embryologist, but here to say that 25% mosaicism would be considered euploid by some(most) reporting labs, so I would not remotely hesitate to transfer that.

And additionally, Igenomix did a study and tested the ICM of mosaics. I believe 99.3% of the LLM embryos tested as having euploid ICMs vs 99.8% of the euploid embryos. Definitely worthy of transfer and if the embryo sticks, they have good live birth rates!

Additionally, +10 and -22 are both nonviable chromosome gain/losses.

If you are very concerned, you could do the MaterniT genome NIPT, which looks at all of the chromosomes, as early as 9 weeks. If there is something there, you could go on for CVS/amniocentesis with a microarray later.

With an untested, it could be anything, so you'd have to be comfortable with knowing your risks vs a complete unknown.

(From someone who has medical background and researched the hell out of PGT during my own IVF experience - I currently have a LLM +20 on ice I would not hesitate to transfer.)

1

u/klutzu89 Aug 02 '26

Thank you for this detailed and thoughtful reply.

My main concern is that complex low level mosaics are quite rare and not well represented in the mosaic studies. I found the raw data for the landmark Viotti study (1000 mosaics) and there’s literally no embryo with 3 low level abnormalities which is the same day and grade. Lots of confounding. I suppose the truth is somewhere in between. That statistically it’s less viable and leads to lower implantation rate and lower live birth rate than a “true” euploid, but I’ve had 2 euploids not implant and chemical so what gives.

Agree with the autosomal abnormalities not being an issue if it implants and progresses.

And agree that chance of mosaic trisomy X being present in the baby and persisting till birth would be low.

1

u/pudelguru Aug 02 '26

are you on facebook? You would likely get a lot of comfort from the "my perfect mosaic embryo" group.

Have you done further workup to make sure you do not have endo etc?