Hmm . . . interesting question for, what I assume, is a very challenging situation to be in.
I actually have a friend who knew, part way through her pregnancy that something was going to be ‘wrong’ (sorry, I’m up late with pregnancy-related insomnia and can’t think of a better, more politically correct word) with her baby. The doctors thought that the baby might have a heart condition. My friend, as you, opted not to have an amnio and, in hindsight, knows that that was definitely the right decision for her and her family. Her baby is over a year old now and it turned out that he has Downs Syndrome. I have never thought to ask her if, once she knew her baby had Downs, they reconsidered the name they had chosen (which actually is a fairly common name). I know meanings mean a lot to them and, I imagine, that is what they considered more than whether or not the name was common.
The name we have chosen for the baby we are expecting means “healthy” and, earlier on in my pregnancy, there was the potential for complications due to a virus I was exposed to through my children. I have been cleared of any complications related to that virus, but sometimes I still wonder if everything will be okay. Regarding the name we have chosen, I wonder about its meaning and whether or not it would be ‘appropriate’ (again for lack of a better word right now) to use it if our baby wasn’t ‘healthy’. Then I think that maybe we shoudl still give her the name because we really like the name and that, instead of the name’s meaning being descriptive, it could be a prayer/hope/wish that we bless our child with.
I guess, from both of these examples, what I’m trying to get at is, for me, what I think would be more important to me than how common the name is that I chose in a situation like this, is whether or not my husband and I really liked the name and the significance of its meaning. We generally consider a name’s meaning anyways, but I think if we were in a similar situation, we would find a name’s meaning even more important.
I think what you are getting at, with your question about choosing a more common name, is whether or not a child with special needs would ‘stick out’ even more if his or her name didn’t ‘blend in’ with the names of other children around him or her. I think I would stay away from really outlandish, super quirky, realy unusual names or names that are really difficult to spell or pronounce (though anything that would fall in those categories isn’t really my style to begin with). Other than that, I don’t think it would be necessary to choose a really common name. I realize I’m not really giving any reasons to explain why I think this. Sorry, I’m finding it hard to explain myself.
I’m not sure if any of that helps. I guess, the other thing I would suggest if this is a significant concern of yours (the name choosing), is to talk to someone with personal experience – another person with a child with Downs Syndrome, someone who works with families of children with special needs etc.