i was big on packing light so the fewer things the better.

lots of black undies, if you prefer under the belly bonds make great maternity ones and you can keep wearing them later.
pj pants and t shirts and singlets.

I never used to wear pjs. but now I have 2 kids and well the more you have to get up at a moments notice the more you start to wear them.
Tracky dacks are great because they feel more supportive than pj's and are usually black or blue in my world so they can hide some sins.

I do recomend having a sleep outfit and a daytime outfit, just so you don't feel yuck, it's also too easy to wallow in bed in hospital, so having to change forces you up, plus you don't feel as frumpy and grose when visitors arive.
most maternity wards are kept at a certain temp for bubs so you will be warm, but they also don't give you many blankets

when you go into labour put something comfy on before you go to the hosi, and if for any reason you need a drip, take any bras, or difficult t shirts off first, they are a bugger to get round a drip.