I'd firstly advise packing the damn thing well in advance! I went into labour at 37+4, and hadn't packed a bag thinking I had oodles of time. So at 3 in the morning I'm asking hubbie to go up into the loft and find my suitcase! Whoops.
To pack:
Lots of Maternity pads - at least 2-3 packets.
Proper knickers - can't bear those disposible nasties, so I got some cheapie knickers from Asda - pk of 3 for ??1, I bought loads and just threw them away with each pad change.
Day and night clothes for you.
Toiletries including ear plugs - especially if you intend to sleep and you're in a bay with other mums and babies.
Moist toilet tissue or baby wipes for those after birth wees and poos - ouch!
Nappies, sleepsuits, and hat for baby.
Camera.
Change for car park and phone. Phone numbers of people you want to phone.
Magazines, books, things to do.
Snacks and drinks - especially for partner as labour can be long and boring for them!
Flip flops - I found slippers to hot.
Not bother packing:
Formula - most hospitals have the main brands in stock - but check with your hospital - I packed some ready made cartons and didn't need them.
xx.