I used to always sleep in a T-shirt or nightgown, and this was more than adequate well into third trimester. After a certain point though, the belly was just too big for the T-shirt to comfortably fit over. I also realized that I would need something with nursing access, as I figured I’d be nursing the baby all day and all night long. I needed it to be still ultra comfortable, hopefully stylish, and I didn’t want to pay an arm and a leg!