I've mostly seen LO's in hospital attire but I've also seen them in full outfits and gowns brought from home. We just kept LO in the kimono t-shirts that they put her in and wrapped her up with a swaddle. It was easier to undress her when she was falling asleep during nursing plus it seemed easier for them to do all of the exams on her.
What did you do? I think for a second child, I'd still just keep them in the t-shirts until it was time to go. I also just really loved those t-shirts for the first month of her life though. They made things so easy!