Should I or should I not get my son circumcised

I am seven months pregnant with a baby boy.  My mom told me that the hospitals will automatically circumcise unless told not too.  So she saying I should make up my mind ahead of time on whether or not I want my son to be circumcised.  I am doing this by myself  since my son father died in a car accident.

I have be told  many different things about this issue.  That it is better for you not to circumcised because boys that are un-circumcised have a better chance not contracting sexual diseases.  Is that true?  However on the flip side of the issue, I am told it is better to circumcised due to looks and how it may effect him when he is older.

So do I do nothing and let him make that dission when he is older?  If I do won’t that cause him more pain then if I just do it when he is a baby?  I asked my doctor but she just says it is a choice I need to make.   Any advise would be helpful in helping me with this.