Mosaic embryo has resulted in pregnancy, now to do CVS or amnio testing?

[sathwa]

I’m nearly 7 weeks pregnant after transferring a mosaic embryo (monosomy chromosome 4 on some chromosomes - not all). We will do a Percept test but have also been advised I may need CVS or amniocentesis diagnostic testing. Has anyone else had experience with this? Which testing was recommended to you? I’m 42 years old.

[SSecret Squirrel]

I haven't been in your exact position, but do have a daughter with a mosaic chromosomal disorder.

Personally I would go for the amnio over the CVS. Reason being (well with my daughter's condition anyway) it is possible the mosaicism can be confined to the placenta only. Rare but it can happen - google "Confined placental mosaicism" for more information. The way it was explained to me is that an error can occur sometime after the first cell division, so on say the fourth cell division. There are two cell lines present, often the best cells go on to form the baby, some form the placenta and some die off.

What this means is the CVS will show you the genetic makeup of the placenta while an amnio will show the genetic makeup of the baby. For that reason, I would go for the amnio.

In my daughter's case I didn't have any testing. Her placenta was tested after birth and 100% of the cells tested cam back positive for the condition. The condition is incompatible with life, so for her to be alive she is either a low level mosaic or doesn't even have the condition. Her blood and skin tests came back negative, however she has some dysmporphic features and the paed believes she has low level mosaicism.

Having said that, my thoughts are based on the specific condition my daughter has and you would be best to be guided by your care givers.

[SJ565]

I had an amnio for the reasons listed above (cvs vs amnio).
One thing to consider is the timing- the amnio is done later- I had mine at about 18w from memory. So if you decide you will take action based on the amnio, this may affect the choices you are able to make.
I went with the amnio as I wanted to be sure it was the baby, not the placenta we were testing

[sathwa]

I haven't been in your exact position, but do have a daughter with a mosaic chromosomal disorder.

Personally I would go for the amnio over the CVS. Reason being (well with my daughter's condition anyway) it is possible the mosaicism can be confined to the placenta only. Rare but it can happen - google "Confined placental mosaicism" for more information. The way it was explained to me is that an error can occur sometime after the first cell division, so on say the fourth cell division. There are two cell lines present, often the best cells go on to form the baby, some form the placenta and some die off.

What this means is the CVS will show you the genetic makeup of the placenta while an amnio will show the genetic makeup of the baby. For that reason, I would go for the amnio.

In my daughter's case I didn't have any testing. Her placenta was tested after birth and 100% of the cells tested cam back positive for the condition. The condition is incompatible with life, so for her to be alive she is either a low level mosaic or doesn't even have the condition. Her blood and skin tests came back negative, however she has some dysmporphic features and the paed believes she has low level mosaicism.

Having said that, my thoughts are based on the specific condition my daughter has and you would be best to be guided by your care givers.

Thanks for your advice. Wow that must have been quite stressful in the early days of motherhood. I looked up confined placental mosaicism and realise this is something our fertility specialist advised could happen with a resulting mosaic embryo pregnancy. It’s a worry but we will get all the testing that we need. The amnio sounds like best practise I just worry about the timing of it being so far into the pregnancy if we have to make a tough decision.

[SSecret Squirrel]

Thanks for your advice. Wow that must have been quite stressful in the early days of motherhood. I looked up confined placental mosaicism and realise this is something our fertility specialist advised could happen with a resulting mosaic embryo pregnancy. It’s a worry but we will get all the testing that we need. The amnio sounds like best practise I just worry about the timing of it being so far into the pregnancy if we have to make a tough decision.

Yeah the timing of the amnio is the biggest worry. I didn't find out I had issues with the pregnancy until around the 21/22 week mark. For lots of personal reasons decided against the amnio, although in hindsight it would have been helpful.

[sathwa]

I had an amnio for the reasons listed above (cvs vs amnio).
One thing to consider is the timing- the amnio is done later- I had mine at about 18w from memory. So if you decide you will take action based on the amnio, this may affect the choices you are able to make.
I went with the amnio as I wanted to be sure it was the baby, not the placenta we were testing

Thank you. I agree on the amnio but that’s the very worry I have. The timing is quite far into the pregnancy to get a definitive result, and I worry about the psychological impact of that. Did you have a Percept or NIPT test first that flagged a condition that then required the amnio? I feel for you having to go through that xx

[SJ565]

Thank you. I agree on the amnio but that’s the very worry I have. The timing is quite far into the pregnancy to get a definitive result, and I worry about the psychological impact of that. Did you have a Percept or NIPT test first that flagged a condition that then required the amnio? I feel for you having to go through that xx

Yes, the NIPT came up with an 80% chance. It was a day 3 embryo, so we hadnt done pgt/pgs.
Would the condition affecting your embryo be shown via NIPT?
With the amnio, you can pay extra for FISH results in 24-48h, or wait for the more accurate results about a week or two later. I'm in melbourne, so our times were a little quicker (no transport delays).
In the end we decided to do the amnio to make sure it was "just" the Trisomy shown on NIPT. Because that Trisomy we could manage, but if it was that Trisomy plus something else, then that would change things.
It was a horrible decision to be faced with, and to have to wait to amnio time is also horrid. Everyone else is excitedly discussing nursery furniture and gender, and meanwhile you're thinking about catastrophic issues, maybe having to terminate, or perhaps a life for you and your child that you never imagined. It is very lonely. I hope you have friends and family around that you can talk to x

[sathwa]

Yes, the NIPT came up with an 80% chance. It was a day 3 embryo, so we hadnt done pgt/pgs.
Would the condition affecting your embryo be shown via NIPT?
With the amnio, you can pay extra for FISH results in 24-48h, or wait for the more accurate results about a week or two later. I'm in melbourne, so our times were a little quicker (no transport delays).
In the end we decided to do the amnio to make sure it was "just" the Trisomy shown on NIPT. Because that Trisomy we could manage, but if it was that Trisomy plus something else, then that would change things.
It was a horrible decision to be faced with, and to have to wait to amnio time is also horrid. Everyone else is excitedly discussing nursery furniture and gender, and meanwhile you're thinking about catastrophic issues, maybe having to terminate, or perhaps a life for you and your child that you never imagined. It is very lonely. I hope you have friends and family around that you can talk to x

Oh gee that would have been so stressful, the long wait between NIPT then amnio and then another delay in getting the amnio results would have been so hard. Especially if the decision meant a termination. I’m trying so hard not to think 3 steps ahead. The Percept test should show whether the condition is present. But the Percept test only measures maternal DNA and fetal DNA from the placenta, not the baby. If we get the all clear on that test I’m unsure whether that means we still have to do an amnio to ensure baby is not affected. We will chat to the genetic counsellors at Melbourne IVF who will take us through all the scenarios. It’s a lot to take on board!

[Frankie1]

Hi, so yes I had a cvs when the nuchal translucency was over the magic number at the 12w ultrasound. I was 39 and conceived naturally. The obs wrote the pregnancy off. Outcome was a perfectly healthy baby, now 4.
Split up, now with a donor dad, from 42yr old frozen eggs, I transferred two fresh embryos timed with my cycle and thought when both implanted I would need the same. So my GP referred me to the WCH in Adelaide and I had an US and blood tests, and risks were over a thousand for a trisomy. Because of this they said not to do a CVS or amnio.
With a CVS they take a sample from the placenta, and in some cases, the placenta can have an extra chromosome or missing chromosome, so they would need to follow up with an amnio. CVS can be done up to 13w6d or something, amnio after this.
At the 6w US there is also a relationship with yolk sac size and chromosomal abnormality. That is the risk increases when it is above 5mm (from memory).
Try and get a referral to your states women's and children's hospital if you can, they'll be on the ball.

[sathwa]

Hi, so yes I had a cvs when the nuchal translucency was over the magic number at the 12w ultrasound. I was 39 and conceived naturally. The obs wrote the pregnancy off. Outcome was a perfectly healthy baby, now 4.
Split up, now with a donor dad, from 42yr old frozen eggs, I transferred two fresh embryos timed with my cycle and thought when both implanted I would need the same. So my GP referred me to the WCH in Adelaide and I had an US and blood tests, and risks were over a thousand for a trisomy. Because of this they said not to do a CVS or amnio.
With a CVS they take a sample from the placenta, and in some cases, the placenta can have an extra chromosome or missing chromosome, so they would need to follow up with an amnio. CVS can be done up to 13w6d or something, amnio after this.
At the 6w US there is also a relationship with yolk sac size and chromosomal abnormality. That is the risk increases when it is above 5mm (from memory).
Try and get a referral to your states women's and children's hospital if you can, they'll be on the ball.

Thanks Frankie1. I’m with Melb IVF and have just done the Percept NIPT test. If it comes back high risk we’ll be going straight to an amnio as that tests the baby’s DNA not the placenta. I remember for my last pregnancy at the 12 week ultrasound, based on my age alone we were quite high risk for Down’s Syndrome but I’d already had the Percept results showing it was more like 1/10,000. It’s so worth doing these extra tests for peace of mind.