Just to clarify based on what I've been told...

From what I've been told, the false positive rate is not just high for women who are AMA- it is true across women of all ages. The risk ratio go up somewhat based on age alone for women who are AMA, but that is expected given the actual overall odds risk r/t age. However, false positives are very common for women of all ages (and even more so for women who did IVF d/t higher HCG and lower PAPP-A levels especially for the "part I" tests- some labs take this into account and others do not which is something to be aware of). Just wanted to add some info I got from our local genetic counselor in case women who are not AMA look at this later on... Overall though I agree with you- it's really not a fabulously accurate test and hopefully in time will be replaced by the fetal DNA testing once the technology is more proven/perfected.