Does anyone know how accurate an amnio is?

[Nikki2ol6]

I had an amnio done at 21 weeks and I got my first results back the next day which was negative for downs, Edwards and pataus syndrome. I waited a further 15 days for the rest of my results which on the phone the midwife from the hospital told me they were all normal. At 28 weeks I had another scan and the dr said my results from my amnio were normal which is reassuring...... I didn't think too much but now I wonder how accurate they actually are? Does anyone know?

100%. They're the gold standard of genetic testing.

You sound very anxious.

100% as they look directly at the chromosomes.

A quick Google says that an amniocentesis is 98-99% accurate.

I can understand why you are nervous if you've had markers for concern previously - but I'd say that following the amino the risk is incredibly small.
if you need to know with 100% accuracy then you can pat privately for the harmony test, it's approx £500 and just a blood test from you.
It's worth speaking to your midwifery team about your concerns. Mine have been incredibly patient and reassuring.

Drinkyourmilk, Harmony is less accurate than an amnio.

amnio takes Fetal DNA from the fluid directly around baby - therefore it's 100% accurate as you're looking directly at their genetic material. If you have a negative result then you can relax

NIPT tests takes Fetal DNA from the bloodstream of the mother (which includes her DNA/placental DNA and other DNA [depending on multiple births]) - so there is a margin of error and hence why the test is not 100%. it is therefore labelled as a screening test.

Thank you everyone I did ask them how accurate it was at the time when I signed the forms and she said it will give you a yes or no answer but that's all she said. And yes very anxious about it all