One of our local newswomen here had the exact same thing as Kate. She was off the air and on bed rest for quite a long time, definitely longer than the initial three months of pregnancy. She eventually was okay, though, and had a nice healthy baby.
I'd like to think this is God's way of protecting poor Kate from the scrutiny for a while, so she can get used to being pregnant and not have to do that with cameras in her face recording every move and every pound. We all know the media isn't going to leave that poor woman alone for a second after this announcement.
I think that's going to be one awfully cute little baby!!