I had a 1/82 chance at 26yrs old with DD, based solely on my bloods, the scan was fine, but my bloods were very bad. we opted for the amnio just so we knew adn could be prepared. The result would not have changed my decision to continue with my pregnancy. this is a completely personal decision and is a very hard one to make. I found the procedure itself very painful, and as DD tried to grab the needle, my uterus had to be punctured twice which meant it was longer than normal as well. The results were all clear, and it really helped me to know where to go from there. Has your dr told you the blood tests can be an indication of other things as well? I was told the low PAPP-A and high HCG could also be an indication of a heart defect which was ruled out at 20 weeks, or could be an indication of placenta issues which were ruled out at 32weeks. I would definately talk to a genetic counsellor, and the advice to get the procedure done by an experienced specialist is really good advice as well. Goodluck with your decision and i hope whatever happens, you have the best possible outcome.