NIPT

[letstal]

The NHS only give a high or low chance in the NIPT for the Down syndrome screening. Does anyone know the NIPT cut off numbers?

1 in 10000

The nurse told me it was over 99.9% accurate. The most likely reason for innaccuracy is if your baby is a "chimera" and has different placental DNA to the DNA of the foetus, this is RARE. So if it says it is low... it's very low - less than 0.1%.

If they don't get a sample that gives a clear result, they tell you.

Sorry you didn't get numbers, it must be a trust by trust thing, mine had the numerical result on it too.

@JD90 what you have highlighted is for combined test not NIPT. Some NIPTS give a numerical results and some don't but if you have got low result.

Ah yes my mistake I was thrown by the mention of NHS as I've only known of people having them privately. Though am aware that some people do get them on nhs if previous results are higher risk.

A study I found lookingn at accuracy of NIPT test results for 10,000 pregnancies showed for DS it was 98.2% accurate. This included results that came back as inconclusive, false positives (ie they tell you you are high risk but you don’t have a DS baby) and false negatives (ie they say you have low risk but you do have baby with DS) so if you come back as low risk it is going to be better than 98.2% accurate.. if that makes sense.. but not 100%

I just got results this morning from a private NIPT, emailed them back asking what "low risk" axtually meant and they replied "The presence of an anomaly is high risk, the absence of the anomaly is low risk. There are no risk thresholds for NIPT"

Which isn't hugely helpful but with some more googling it seems that is generally the case, they don't attach a numerical equivalent to it.