Down syndrome diagnosis after PGS testing in IVF- looking for experiences of this

[Fs252]

Hi, I’m looking for first hand stories of a downs diagnosis after transferring a pgs normal embryo?
I’ll be posting this is other threads as while it must have happened, I cannot find an actual first hand stories of someone with this experience, anywhere on the internet.
I have been given a 1 in 5 chance based on an NT measurement of 3.5mm, my age 40, ivf baby, my bloods are normal.

No, PGS checks for a full set of chromosomes, PGD checks for one specific thing. I am completely baffled to get this result on the combined test. The embryologist at the clinic said that the nhs shouldn't have bothered offering me the nuchal as it's a far less accurate test! But it's not 100%, around 98%. I hope I'm not in the 2% of mistakes.

But as my post says, I cannot find any stories, first or second hand, where a baby has had downs after PGS testing. My hope is that it almost never happens.

I think it's most likely that the screening test has come back at a relatively high risk because it's a fairly broad-brush screen which factors in age, NT and some blood results. It's designed as a population screening tool, to flag up a clinically relevant proportion of cases in which there could potentially be an issue, so that people can then decide if they want additional investigations. It's not diagnostic by any means.

What you could do is consider if you would want additional investigations such as NIPT - there are some really good discussions on here about how NIPT can be used in pregnancies post-combined test. Again, it's not diagnostic, but may give you a more accurate assessment of the likelihood of certain conditions (always make sure you know the predictive values of any tests though!).

It's also possible that genetic mosaicism could be a factor, although this is much less common. In mosaicism, some cells in a person's body have different genetic material than others (eg. A person with a mosaic form of Down Syndrome would have some cells with 3 copies of chromosome 21 and other cells with 2 copies). People with mosaic forms of a lot of conditions can tend to have better clinical outcomes (eg. A family friend who lived independently and maintained employment and a social life, who had mosaic Down Syndrome).

There are no 100% guarantees, I'm sorry, but from the information you've given, I think the likelihood is that your embryologist is spot on and you shouldn't worry too much about the combined test, although you may want to consider NIPT if you feel you need extra information at this stage.

1 in 5 seems very high.
I think i read high nt could be heart issues instead.
I would go for the downs blood test. As a pp say i imagine baby could still have mosacism.
If it's not downs maybe they need to look at the cause of the nt

@Scirocco thanks for replying. I will certainly be going with the NIPT test and hope to have that today. I was offered it at 10 weeks by my ivf clinic but I declined as I thought I didn't need it having already had PGS! Mosaicism is a worry. How unlucky will I need to be. That's why I'm searching for stories!

@HSHorror it's very high. It's shocking. I'm wondering although the screening midwife said my bloods were normal but that perhaps they exceed the cut off by a very small amount. Also I think they have input my age as 40 and not 39 which is what I was at egg collection.

@CrazyNeighbour I hope you're right.

I think it's usually age you will be at birth but i guess with ivf that can be quite out.

Although it's high, it's still 80% likely there's nothing going on. As someone said, age/nuchal fold etc gives a broad population likelihood but it isn't science, it's statistics. 20% of people with the same numbers as you will have a child with DS but if your earlier tests mean that shouldn't have happened, it seems very likely you're in the 80%

@SleepingStandingUp I hope so! Thanks for replying. Ive also just read that women on progesterone supplementation which I've been on a high dose of, can increase NT measurement. There's a couple of studies that showed a significant difference and one that showed it didn't make a difference. I know I'm just desperately looking for hope.

I think you need to have an idea what you'd do if baby has got T21 or MT21 - of you wouldn't continue then get the NIPT or whichever vyoi choose and get as close to definitive as you can ASAP.
I wouldn't have an amino because of the risk of miscarriage, however low it is
If you would continue anyway then you could wait for the 20 week scan or just accept what will be wil be

Hi @Fs252 I’m afraid I can’t help with the ivf screening part but can share my experience of high chance screening. Our son’s NT was 4.7mm and I was 39 during the pregnancy - we had a greater than 1 in 4 chance of DS. The high NT measurement and my age accounted for this with my bloods a little off. 3.5mm NT is at the upper end of normal limits I think - interestingly I too had progesterone in the first trimester due to recurrent miscarriage. Anyway our son had a low risk NIPT, clear amnio and heart/anomaly scan - and he arrived safe and well last summer. A high NT can be something or nothing - I really hope it’s the latter for you and your baby Xx

Thank you @jmm499 for taking the time to tell me your story. I'm so pleased it worked out OK for you. Gives me hope. I'm in tomorrow for the scan with the consultant.

This is total hell, I'm sorry you've had to experience this yourself. Xx

Sending you huge hugs @Fs252 - it is such an impossible thing to go through. The odds are in your favour though particularly with the screening you’ve had pre-transfer. But I know it’s almost impossible to rationalise things when it comes to your baby, no matter how small the risk. I remember thinking that it must be almost guaranteed to have a DS diagnosis with the odds I had because I hadn’t heard of those kind of stats before. But my screening midwife said she’d had a family with a 1 in 2 chance whose baby didn’t have DS. It’s so hard going through it though - I’m thinking of you. Have you had your NIPT? I hope the scan goes well tomorrow xxx

@jmm499 thank you so much ❤. No not had the NIPT yet but I will before an invasive test. The cvs actually checks the placenta cells which is what the pgs tests for! Will go for the amnio if I absolutely have to.
The embryologist at the clinic just called and said that she personally looked at the chromosomes herself, as well as sent the biopsy to a highly reputable lab which are looked many times, and the embryo was chromosomally normal when transferred.
They send hundreds of biopsies off and never once has there been a mistake in her experience. Gives me some more hope.
I will be so unlucky if this becomes a downs diagnosis. You're right though, even when I try and rationalise, you cant quite seem to calm down. It's awful.
Thanks for your supportive words. I'll update this thread ❤

Oh OP. What a stressful time!

I'm with your embryologist on this one.
The NHS is claimed to be combined 'test' but I personally would put it in the category of guessing games. At 40 your risk will auto be raised by a lot purely by the numbers of your age! Then with IVF pregnancies you often find that women have slightly lower Papp-a levels. And a NT measurement which is still within range but classed as borderline will bring your "risk" from the combined screening sooooo much higher. It's actually disgusting that they still use it this way. (Never mind the many undetected cases of T21...)
I know this is an anxious time and I'm sorry you're being put through this, but I honestly think your baby is absolutely fine and is really hope you get your answers soon.

@Fs252 aww I think that’s really encouraging to hear from the embryologist ❤️ There’s lots of hope to hold on to 😘 I’m with the PP :) I’m rooting for you and your baby! Hang in there xxx

@NoCallerID thank you for your encouragement there ❤ I really think the language used around this test is terrible. I feel almost discriminated against bc of my age. What this test hasn't taken into account is what I've already done to mitigate the risks within my ivf treatment.

@jmm499 yes it was good of her to call. The clinic are keen for news around this as well, as you can imagine. They aren't worried. Thanks so much again for the responses all ❤

It does sound likely to be fine.
Are nhs not stabdard using nipt yet?

@Fs252 Yes, I feel the same. From 35 onwards it just makes massive jumps.
Have you got a NIPT booked? Or does your NHS trust offer them?

@HSHorror no. Since earlier this year most hospital trusts have agreed women are eligible for a NIPT on the NHS only if they had a previous confirmed case of one of the 3 main trisomies. This is now changing for women who have their combined screening on or after 01.06.21 - if they get a high chance result they will be offered a NIPT before CVS/Amnio but it's not replacing the combined test.

@HSHorror

No, the combined screening test is still the first line of testing and then people can be offered NIPT - the idea behind the policy change is that this broad screening picks up people who may be at higher risk than the general population, and then NIPT can be used with more reliable predictive values in this more targeted population.

If a test has, let's say, a 99% likelihood of giving an accurate result, but the condition it's testing for only occurs in 0.001% of the population, testing everyone is going to throw up far more false positives than there are actual cases. But, using it on a subset of the population which has been identified as having a higher rate of the condition occurring, means that any positive results are less likely to be false positives. By targeting the NIPT to this population, it's more likely that people at risk will get reliable results which can help inform decision-making.

However, the combined test itself drastically needs an overhaul as its parameters are based on rather out-dated population data.

Just to update this thread, saw the consultant today, had another scan, NT is now 1.54mm and there are no other concerns. I'm going back in 2 weeks for another scan with fetal medicine and we can decide between now and then if we want the amnio. The baby will have a heart scan at great ormond St between now and then also.
Consultant said no point doing a NIPT as I've already had a highly accurate screening with PGS and she agrees that the chances of the baby having downs is very low.
She said I should be very reassured by today's scan but of course a scan still doesn't tell us for sure about any genetic issues.
So relieved. Not sure if we will do the amnio now but we will give it some thought.

@Fs252 this is great news! Very reassuring ❤️ Will be thinking of you over the next few weeks - you’ll know the right decision re the amnio. I was in 2 minds for quite some time and one day I woke up and decided I needed to know as much as possible (just because of our high NT which was outside the normal range). The only way I could feel comfortable about it was to go and see Prof Nicolaides at the FMC for the procedure - obviously cost a lot but I felt at peace in my decision. I guess what I’m trying to say is that you will know whether it’s something you should have done or not 😘 And whichever that is will be the right one ❤️ Sending you and your baby love Xx

@jmm499 thank you for the advice. That's how I approach many things in life with that exact theory, the answer will present itself. I'm glad I can rely on that in this situation too. Thanks again for taking the time to share your experience, really appreciate it ❤

@Fs252 you sound very wise! Someone said to me once if you can’t make a decision then you’re just not ready to make it yet, that’s brought me a lot of comfort in various situations! The right answers are always inside of us ☺️ I hope you’re enjoying a little respite tonight after the last few days of worry, rest well 😘 Xx

@jmm499 I am indeed. And I'll sleep a bit easier tonight. I got to see my baby in amazing detail today and that was really special 🥰