What not to say part one:

Don't Complain About Your Pregnancy by RESOLVE
This message is for pregnant women-Just being around you is painful for your infertile friends. Seeing your belly grow is a constant reminder of what your infertile friend cannot have. Unless an infertile women plans to spend her life in a cave, she has to find a way to interact with pregnant women. However, there are things you can do as her friend to make it easier.
The number one rule is DON'T COMPLAIN ABOUT YOUR PREGNANCY. I understand from my friends that, when you are pregnant, your hormones are going crazy and you experience a lot of discomfort, such as queasiness, stretch marks, and fatigue. You have every right to vent about the discomforts to any one else in your life, but don't put your infertile friend in the position of comforting you.
Your infertile friend would give anything to experience the discomforts you are enduring because those discomforts come from a baby growing inside of you. When I heard a pregnant woman complain about morning sickness, I would think, "I'd gladly throw up for nine straight months if it meant I could have a baby." When a pregnant woman would complain about her weight gain, I would think, "I would cut off my arm if I could be in your shoes."
I managed to go to baby showers and hospitals to welcome my friends' new babies, but it was hard. Without exception, it was hard. Stay sensitive to your infertile friend's emotions, and give her the leeway that she needs to be happy for you while she cries for herself. If she can't bring herself to hold your new baby, give her time. She isn't rejecting you or your new baby; she is just trying to work her way through her pain to show sincere joy for you. The fact that she is willing to endure such pain in order to celebrate your new baby with you speaks volumes about how much your friendship means to her.
http://www.resolve.org/support-and-services/for-family--friends/infertility-etiquette.html