Here are two posts that I came across discussing things we do NOT need to hear and remind us all to think before we speak. 

http://eyeheartinternet.wordpress.com/2009/07/05/10-things-not-to-say-to-your-infertile-friend/

and then an additional one inspired by the first one….

http://zenpeacekeeping.typepad.com/zen_and_the_art_of_peacek/2009/09/10-things-you-probably-shouldnt-say-to-a-friend-who-doesnt-have-children.html