Offered Diagnostic Test - Any experiences people are willing to share?

[Shawla92]

Hello everyone

Just a bit of background :)

I'm a FTM with my partner who also has 0 children. When I found out I was pregnant I was told by my mum that I was a carrier of muscular spinal atrophy (MSA) so I mentioned this at my 8 week booking in appointment and then my 12 scan appointment.

Me and my partner then went to the Genetics Clinic in Manchester where we have just found out that my partner is also a carrier (HUGE SHOCK)

As I am 14 weeks they have advised that if I want further testing to wait till I am 15 weeks for the amniotic fluid testing as this has a lower risk or miscarriage than having a sample of my placenta taken.

I know that there is a 0.5% - 1% risk of miscarriage with the amniotic fluid test which is weighing heavy on my mind as there is a 25% our baby will have MSA and 75% it will either just be a carrier or not have any MSA gene at all.

Has anyone else had this kind of thing to deliberate and what were your deciding factors?

I'm really torn between finding out or just going with it as both can have devastating outcomes.

Gosh how stressful - but I guess good to have this information in advance.
The risk of miscarriage is much lower than 0.5-1% - it’s more like 1/1000 for an amniocentesis. If you’re 14 weeks already then you are past the point of CVS - but that carries about a 1/500 risk of miscarriage.
The decision depends a little on what you would do with that information - try to think whether you’ll be comfortable with not knowing until your baby is born, with 1/4 chance of a severe disorder; whether you’d like to know for preparation; or whether you’d like to know and would consider stopping the pregnancy if the baby was affected by SMA. You don’t necessarily need to make decisions about anything in advance but I think it helps to frame things that way when you’re deciding on testing.
Personally I would do the test. And the amnio itself is really straightforward and only takes a minute or two.

Thank you for your reply - I appreciate it. The rational part of my brain is telling me not to be ridiculous and just do the text but then this tiny hormonal part of my brain is saying " what if you do the text and you're part of that very unlucky percentage that miscarry and then the results come back that your baby was fine"

I know that there are no right or wrong decisions and I can convince myself either way but nice to have others perspectives on the situation :)

Is it spinal muscular atrophy (SMA) that you are carriers for?

If so I agree with the PP you need to have a think about the likely impact of having an affected child and whether you think the information from the test would be helpful in planning the future.

The effects of SMA can very widely from children who are barely affected to children who are very significantly disabled and life limited.
This has a huge impact on families.

The charity Antenatal results & choices exists to support families in the position you find yourself. They have a telephone helpline.

Best Wishes and I can’t imagine how difficult this is for you. Such an unexpected twist.

I used to perform the genetic testing for SMA. Sometimes this was to determine carrier status of parents, such as with your partner. The carrier rate for SMA is actually surprisingly high, so it could happen to any of us (unless we've already been cleared by genetic testing of course). Other times it was for current pregnancies, such as with your current situation. Other times, it would be because there was a VERY sick baby in intensive care, with suspected SMA, and essentially receiving an SMA diagnosis would help decide whether or not to turn off the life support.

I don't mean to say this to scare you, but personally I find I prefer to have all the information I can. There is no right answer, but some people will prefer to find things out in advance and others prefer to wait. Equally, just because you may find something out in advance, DOES NOT MEAN YOU HAVE TO DO ANYTHING ABOUT IT. It just enables you to prepare yourself a little for what may come.

Depending on the result of a genetic test for SMA, there may be some ability to predict likely severity. This may be something which can be done by looking at you and your partner's exact results, rather than needing to have an amnio or CVS, but invasive testing may be needed to confirm. NIPT may be possible, too.

You should've been given access to a genetic counsellor, so please feel free to discuss all your worries and concerns with them - it's what they're there for.

Good luck either way, horrible situation to have to be in.

Thank you all for your advice. After speaking to the genetics councillor we have opted for the amnio test once I reach 15 weeks (I'm 14 at the minute) so we can better prepare.

Hello @Shawla92 could I just ask how long you waited between being referred to your appointment? Hopefully you get some good news at your follow up.

Hi Lou

Well I was dealt with very quickly as if our baby was affected by SMA we would have terminated. I think the referral time may differ between hospitals too. I was dealt with by St Mary's in Manchester.

I basically mentioned that I was a carrier of the fault gene at my booking in app then I spoke to a dr at my local hospital at my 12 week scan (I was 11+4) and from there we had to have an appointment about a week later and see a genetics councilor in Manchester so my partner could get his bloods tested to see if he was also a carrier of the faulty gene (he was) and these results took about 10 days to come through. I was then offered the amnio and advised its from 15 weeks so I had my appointment when I was 15+3.

Once I had the amnio I had to wait 10 days for my results as they will doing a full assessment of the DNA and I believe this takes longer than the 3 days for testing of the trisomies.

Luckily we had good news :)

Hope you're not having to go through too much stress x

@Shawla92 thank you for your reply. How are you getting on with further testing etc. Hopefully you are taking care of yourself, it must be such a difficult time for you both.

My situation is slightly different. I had a younger sibling with SMA and I am planning on ttc. I have been told to expect a wait of around 18months-2 years for testing, I was initially referred 2 years ago and was told I would be seen in approx. 2 years, however the initial referral has been lost .

Thank you again for your response, it was really helpfull to know x

Hi @Lou202020

Luckily our results confirmed that our baby is a carrier of SMA and not affected by SMA so he will just be like me and his dad.

What sort of testing are you having to wait for if you don't mind me asking? I thought it would be as simple as you and your partner getting a blood test to confirm that you are both carriers and then a test on any embryos you conceive (CVS or Amnio) to see if your baby is affected, a carrier or not at all. x