A friend of mine, Matt Pack, sent me the video above of his wife, Grace, going through her last "energy" workout right before the delivery of her baby. She had an easy labour and a healthy child and worked out like this all the way through her pregnancy.
If this doesn't inspire you to maintain your fitness (if you can, medically) throughout your pregnancy, I don't know what will.
NOTE: for those of you reading this post on Facebook, the video won't likely post, so if not, just visit my blog to see her in action.