I had an amnio at 18 + 3 due to a higher risk of Down's. I was absolutely terrified.
The procedure itself was quick and painless and the consultant was lovely and clearly very experienced.
A couple of days after the procedure, we received a phone call saying that there was no sign of Down's Syndrome. We were obviously very happy, and we also found out baby was a boy. It was also our wedding anniversary so really felt we had something to celebrate.
The following week, however, we received a phone call from the hospital saying that further analysis of the sample taken had shown a fault with one of the chromosomes. We were referred to the clinical genetics department in another city, and had to wait a few more days to learn any more.
At the appointment, we were told that they had found a partial deletion of one of the genes and that this could indicate a rare genetic condition called branchiorenalotto syndrome which can cause kidney failure, deafness, and facial deformities. The samples were then sent to Great Ormond Street for further testing. We were distraught, and I wasn't sure I wanted to continue the pregnancy if my child was to have a lifetime of suffering.
A week after that, I received another phone call from the hospital revealing, unbelievably, that detailed analysis of the sample from the amnio had shown that there was no fault at all. Our baby is genetocally healthy!
I'm 36+3 now, and it's been a rough ride. (other reasons too, but not relevant to the amnio). Given the choice again, I'm not sure I'd have had the amniocentesis after all. It caused a hell of a lot of unnecessary worry and pain only to be totally inaccurate with its findings.