I think if you want something to say to a pregnant woman, just say, "You look beautiful!"

I got some of the "all-belly" or "can't tell you're pregnant from behind" comments too, but at the end, the weight went everywhere. So I felt self-concious about comments about how big I was because as Pixie said above, I felt like people were referring to more than my belly. In reality, they probably weren't, but when you're self-concious about the scale tipping to these numbers you've never imagined seeing before, it's easy to get a little sensitive.
Life with Lydia