29 weeks & my baby dilated a kidney?

Depends how much: Many times on prenatal ultrasound somebody sees a slightly dilated or swollen kidney. There can be a little developmental blockage at the junction of the ureter, or just difficulty in nailing down the exact size of the kidney. Sometimes one kidney may grow a little bigger than the other. If there is a big difference, an ultrasound after delivery will be more specific as to a problem.

Ultrasound: Ultrasound images may be misleading. It's best to view us over time to be sure there is or isn't a problem. Sometimes something seen on one ultrasound won't be seen again, or be related to an anatomical problem.