Jen Heath (there's an article about muffin top to abs of steel or something at the top of the "Exercise" section) talked about working out during pregnancy when she was first interviewed for a podcast I listen to called "The Fit Cast". She said she, too, worked out with both her pregnancies (one with a single child, the other with twins) up until the 8th month. She lifted and did some cardio, with no negative effects. She talked about it more specifically...but I've never been (and never plan to be) a mother, so I didn't pay too much attention to the details
She also talks about weight gain during prenancy, and how women tend to go overboard with the whole "eating for two" thing.
Good for you, Kim!
Your abs of steel are totally a motivation for me. I don't know if I want to have abs that defined, but something close would be nice! And if you can look that ripped after having a kid and being close to 40, damnit, I can, too!