Confused about Down Syndrome/Edwards testing

[ml01omm]

Hi

I have just had my midwife booking in appointment, and I am confused about the screening for Down Syndrome.

The Midwife has said that they will only do the test at my 12 week scan. They will take the blood test and do the scan all on the same day.

Then, assuming I am high risk, I assume I'd go on to have the amneosentis (sorry for spelling) to confirm.

In this case, at 12 weeks I would be too late to have the NIPT/Harmony test? Does the NIPT test replace the amenosentis, or is it just a more accurate/less invasive version of the NHS initial blood test and scan?

I want all the screening, but want to try and make it as least invasive as possible.

Should I pay to have NIPT ahead of my NHS tests? Or would I still have to have an amneosentis regardless of whether I was high risk per NIPT or per NHS?

NIPT, although more accurate, will also just give you a probability. It is not a diagnostic test.
An amniocentesis will be offered if you are high risk. It is invasive and carries a risk of miscarriage. I think about 1:100 or so, not entirely sure.
I'd wait for the scan and blood results and go from there.
If you want a definitive answer you'd need to do an amnio.

The NHS look at the scan for brain size anomaly and test hormone levels to calculate risk. NIPT extracts fragments of baby DNA from your blood and does a genetic test in order to again calculate risk. If you come up as high risk you can use amnio to confirm. The NIPT also tests for several other conditions. The NIPT yields better results so if it matters to you then you might want to pay for it.

Nhs Scan and bloods will give you a probability, not particularly accurate, lots of variables. If that comes back high risk (or if you wanted to for any reason really) then you have the NIPT/Harmony. It’s another blood test, not diagnostic but very very accurate, around 99.9%. Not invasive. Then if that comes back as high risk, amnio which is invasive, risk of miscarriage but gives you 100% definitive answer.

The results from my 12 weeks scan came back high risk for Down’s syndrome, 1 in 75.

I then had an appointment with a specialist screening nurse who explained our options.
We then had a NIPT test, which gave us a negative result.

If it was positive we would have then been offered an amniocentesis.

I would definitely wait until you have a the results off the 12 week scan before you pay for any tests.

Unless you are high risk for a particular reason e.g. age the. I would wait and see what the NHS screening says before considering NIPT. There is no set cut-off for NIPT, it can be done after 12 weeks.

The harmony/nipty/serenity test is very accurate. It is a blood test. It is the combined screening that is offered on the nhs that is less so that gives you a probability. The amniocentesis is very accurate but you would never have that unless you came back high risk.

I am a sonographer and for my most recent baby I chose to have the serenity test privately. I still had the nuchal ( the scan part of the combined screening) as that can also indicate heart abnormalities but I didn’t have the bloods part of the combined screening. I would never have an amino without some indication from one of the other tests.

I would add you can have the private blood test from 10 weeks I think.

Thank you everyone.

I had gotten very confused and thought I could only have the NIPT testing at 10 weeks, not *from 10 weeks.

It all seems clearer now. I will have NHS test, see what happens ( I am concerned because of my age) and then see whether I need the NIPT. I know my healthcare trust does not offer it - either on NHS or for a fee.