Car seat

So I live in Houston,Tx I plan on delivering at memorial Hermann hospital. I installed the car seat base into my car..my mom says when it's time to go home with the bby and we are in her car or my boyfriends car they won't let me take the bby home without the base of the car seat... My question it is that true? Or who do I need to contact to find out the facts I don't want any surprises when I'm trying to leave the hospital