You know I have read so many threads where posters are offended and upset about questions friends have said to them about their pregnancy or new born baby. IMO these are usually just general questions where the questioners rarely care about their answers.
But as mums we are all aware what a big thing it is to be pregnant and have a new baby. So it seems really rude to just say congratulations to those pregnant and to those who have had a baby just ask what is their weight and name? IMO it is polite to show more interest than just this, to what is a huge event for a friend.
So what questions are okay to ask that won't offend anyone reasonable?