The risks of amniocentesis were already mapped out for you, but I wanted to add some.
Really, the only reason to get one done for health reasons would be if you wanted to terminate the pregnancy if it turned out there was a problem. So if you wouldn't abort no matter what, there's just no point.
Also, false abnormal results are common with amnios. I've heard stories about women who had it done, the doctor tells them there's something wrong with their baby....And they stress over it for *months*...Then the baby's born, and it's perfectly fine. Turns out the amnio was wrong. I wouldn't recommend those things to anyone....Unless they wanted to abort if something was wrong.