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?

[bonzo77]

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

You sound very anxious.

[missyB1]

100% as they look directly at the chromosomes.

[drinkyourmilk]

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.

[SweepTheHalls]

Drinkyourmilk, Harmony is less accurate than an amnio.

[hopeful31yrs]

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.

[Nikki2ol6]

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