If your own kids don't leave you screaming, then the annoying things that people say to you might.
This little walk-through will reveal some of the more common stupid and annoying things that people say to parents, both so that you don't say them yourself and you are prepared and know what to say if you are faced with these questions and comments.
Although I think that I tend to give some of the people who make these kinds of comments too much credit, I think that they often just don't think about what they are saying or how they are saying it. Even saying something like 'why don't you just adopt' to an infertile couple would sound much better if you said 'have you thought about adoption at all?'
When faced with a question or comment that has you annoyed, try to give a quick and contructive answer and then simply walk away or change the subject. If it is someone that you know and think might learn from the experience, you might mention why what they have asked is rude or insensitive, even though they might not understand or appreciate your advice.