I brought extra hair ties, chapstick, my pillow from home, phone charger, camera with charger, clothes for Baby and me to go home in, and toiletries. Aside from that, we didn't use much. Everything else was provided. It's always wise to see what is provided at the hospital where you will be delivering, because it does vary widely. Most provide diapers, blankets, hats, and shirts for Baby, and gowns and socks for Mom. Beyond that, it varies, so it's worth calling and asking.
Also, we kept a list of anything that would need to be packed in addition to the stocked back (such as toiletries that I use daily) so that in the whirlwind of heading to the hospital, we'd know what to pack. It came in extra handy, as DH had to run home and get the bag after I was admitted!
at 12:56 AM on Nov. 17, 2010