Hi I can completely understand your question and I think some people have been a bit insensitive with their answers. It is easy to throw a Bible verse at someone without truly understanding your situation. This is important to you. I feel the same way about it. If I had a son then my parents would expect me to have him circumcised and although I know the Biblical answer is that your child doesn't need to have it, but in circumstances what do you do? Do you have your child circumcised because there are clinical reasons that show it is more hygienic and healthy for some boys or do you risk your family falling out with you? I think this is a secondary issue and I think that God would understand either way. Yes in the Bible it says boys do not need circumcising anymore, but many people do. Adults get circumcised that are Christian and it is a much more serious job when they are older. When your child is born they will not remember being circumcised. My husband often says that he wishes he was circumcised because of the fact men who have been circumcised are much more cleanlier.
I think there are much more worse things that people can do that harm their child. For example Christmas. Christmas is fine, but if you teach your child about santa it is a big fat lie. I mean think about it santa is satan spelt the other way and when your child is older you have to tell them it is a lie. When you try to tell them that Jesus is real they will think you are lying to them. Yet many Christian families carry on this lie year after year without batting an eye lid. Yet when you mention circumcision people tell you it is wrong and the Bible says this about it. What does the Bible tell us about father christmas. Does the Bible teach us about it? I think not. So it is up to you, but don't listen to anyone else but, you. If in your heart you feel it is right then go ahead and do it if not then don't. I hope this helps.