I'm not sure how helpful this will be...but I know that Moving Comfort and Nike make maternity "exercise tops". They are made out of wicking material, may or may not have zippers, and don't have pockets. I was just thinking that they would be less $$$ than a full-on jersey (if you could even find one). Isn't that what the captain is for anyhow? Easy pocket access?

Trek is one of the few companies doing little-bitty bike gloves and clothing, so check you dealer. I know Cannondale and Sugoi used to do kids stuff, but I haven't seen any in a few years.