I know what you're thinking, the robe is for the hospital. Well, yes, it is. If all goes well and a woman gives birth vaginally, she might only be in the hospital 2 nights. I rushed things (surprise!) and only spent one night. So having a nice robe is good to have when shuffling around the maternity ward and greeting loved ones.
BUT...once you get home you're gonna be spending a lot of time in that robe too.
For one, the first week or two you might not get out of your robe until lunchtime. And even after you get into a routine, you still might want to stay in your robe...Yes, after the kid arrives, you might find that comfy desire to stay in your robe, drink your tea or coffee, and enjoy those precious few minutes before everyone else wakes up.
Because you'll be spending some time in your robe, I suggest you get two. At least. And seriously, what is better than a nice warm fluffy robe straight from the dryer?