Amniocentesis / CVS Dilemma

[Parents2B]

My partner and I are expecting our first baby. My wife is 42 and I am 40. It is the first child for us both. We are currently at 12 weeks.

Our Harmony test results were good and no risk of Downs/Patau /Edwards. We thought we were all good.

We had our 12 week scan and the NT thickness was above average (3.7mm against an upper limit of 3.5mm). We have no history of medical issues in our family history.

We have been advised to have a heart scan our our baby girl at 14 weeks to see if there is any structural damage and that is fine given it is risk free.

We have also been offered and encouraged to have a Amniocentesis or Chorionic Villus Sampling (before we hit 15 weeks). The reasoning being that the Harmony test only shows results for the three most common problems.

We are so torn on this. Doctor friends of ours have said it is unnecessary given the Harmony results but now it has been offered we feel that it should be something to consider (it is in the NHS in the UK and so wouldn't be offered unless their was a good reason for it).

Our concern is obviously the risk and we have been told there is a 1% risk of miscarriage which really feels too much for us (we wouldn't get on a plane if there was a 1% risk of crashing and so when it is the health of our baby it is even more scary).

Has anyone else had this dilemma and could anyone offer some advice or thoughts as we are really torn, and frankly, stressed out of our minds. Would you think it is worth meeting with a consultant for advice as, to date, we have only been advised by an (excellent) midwife.

Thank you in advance for your kind words and support.

Best Answer usually depends what you would do with the information.

If you know you want option of termination then you need the test.

If you almost certainly would never terminate, then scans during pregnancy would give you as much info as you need before birth.

50 scenarios inbetween those boundaries, of course.

I've never understood why the miscarriage risk of amnio/CVS is usually just played down as I agree with you it's actually quite high. The plane analogy is a good one. I would decline the amnio and CVS too because the risk would be too high for me.

Amnio is less risky than CVS. Remember that the miscarriage figures include pregnancies that would have ended in late miscarriage anyway, and that these tests are more likely to be done on higher risk pregnancies.
A lot depends who does it.
As people say, it depends what you would do with the info.

If it's any comfort I believe the statistics around amnio and miscarriage are decades old and based on out of date practices and technology so the true "risk" of a miscarriage following amnio is much much much lower. The statistics thrown around are based from when amnio wasn't carried out using ultrasound. A danish study of 140,000 pregnancies has since found the risk to be almost zero and another study found it to be less than 1 in 1000.

I thought NIPT did everything that NHS screening did but with a greater degree of accuracy? What exactly are they looking for/ suspecting?

Older couple here too. I chose to have the Natera Panama which is the Harmony test under another name. I also chose to have Natera's Vistara test which screened for about 20 other anomalies and syndromes which they say together total more than the risk of DS. I'm not sure in this instance if those anomolies/syndromes tested are exactly the same as what the CVS/Amnio may be testing for, but the clinician I spoke to Dr. Bryan Beattie at Innermost healthcare in Cardiff personally called me to verify it was a worthwhile test for me and answered about my long list of questions! It is a bit of a niche test so you may not be aware of it but worth having a look and possibly asking the clinic to get him to give you a call for a second opinion anyway. Also do google him, he is a v well respected obst. In the NHS in Cardiff. My results came back within 10 days and was a 2 min blood test. Was all clear and a complete weight off my mind. There are quite a few online resources about it, happy to ping you all the links I found if of use. Best of luck

Also forgot to mention as @twinsetandpearl mentioned if you look at the chapter on this in Expecting Better, Emily Oster has some really useful ststistical insight into where those CVS /Amnio stats are coming from. Some are from the 70s, massively outdated...its on kindle if you need to access the info to make a decision pronto

The hospital staff tried to pressure me into an amnio as the doctors thought our baby had Edward's Syndrome. We refused as we would have the baby anyway and didn't want to risk an amniocentesis incurred miscarriage if the baby was okay. Hospital weren't happy but it was my choice.

The Harmony is a screening test for three trisomies. The NT is measuring the nuchal translucency—if that is enlarged, it can be linked with other conditions not screened for with the NIPT. CVS and amnio are diagnostic tests. Trisomies tend To have a constellation of symptoms that can include other anatomical malformations that are picked up on scans. Sometimes if a screening test is normal but the scan is not, you might be referred for further scans like a foetal echo.

Generally, the NT measurement should be matched against the crown rump length to ensure an appropriate calculation. I imagine you have been recommended further screening due to the measurement and your wife’s age, as the risk of trisomies increases with maternal age.

As someone above mentioned, the big question is what you would do with the information provided by further testing. Trisomies 13 and 18, for example, have a very poor prognosis and most babies with those syndromes will die before birth or shortly after. Trisomy 21 (Down’s) has a much more varied outcome but generally includes significant mental and physical handicaps.
Some people choose to do further testing so they can prepare themselves for any outcome, parenting a special needs child, etc. Some people choose to do further testing so they can terminate the pregnancy. Some people choose not to do anything and just wait and see. There is no right or wrong answer, except what you and your wife will decide is best for you.

It’s good that you’ve had a supportive midwife, but perhaps speaking with a genetic counselor and/or consultant would be helpful as well?

I’m sorry there’s no easy solutions here. I wish you well.

We were told by both a consultant obstetrician and a consultant geneticist that the risk is 1%. I can’t comment on the information given by other posters as to how accurate that statistic is but I guess the point is that the obstetrician who will do the procedure will never be able to guarantee you that it’s completely risk free. Whether the risk is 1 in 100 or 1 in a million doesn’t really matter if you are in the 1, especially if it turns out your baby was healthy.

We were offered an amnio and declined it ultimately because we would not have wanted to terminate unless we were given clear guidance that baby would have no quality of life . We had a risk factor for a genetic condition snd baby was measuring very small at 20 weeks (they couldn’t get the NT measurement so couldn’t do the combined test). However there were no other markers and so for us the 1% risk was way too high.

For what it’s worth, baby was born at a relatively whopping 8lbs 5 and is currently 4 weeks old. So far as we can tell she is perfectly healthy. There is no right or wrong answer to this but yes I would recommend speaking first with a geneticist and then if you are minded to proceed with the consultant who would actually do the procedure.

I had an NT of 3.7mm too. It’s only just over the threshold and apparently it’s 4mm in Europe (but don’t quote me on this!). I had a harmony test (so opp way round the you) which was low risk. Consultant did a detailed anatomy scan and everything looked normal so advised against the amnio. I had 3 cardiac scans.

In your position I would be relatively comfortable in not doing the amnio. It all depends really on what you would do if the news was bad.

That NT is quite high and in my experience if things are off they are off for a reason.
I have a son with sn , his NT was 2.8 but the bloods came back with a high risk in combination for the 3 main ones ..
I had a cvs and was told he was fine . He is 11 and then the micro array was a new test. I believe they do this routinely with the amino and cvs now ..
What I'm saying is just because the baby doesn't have the 3 main ones doesn't mean there isn't an issue . There are a myriad of genetic blips that cause issues and even one extra gene can be devastating ..

Basically as above if you wouldn't abort anyway then don't do it , if you would then do.

Thank you everyone for your support and advise.