Had one of these with my first delivery and had to order another for this baby.  I do not wear it for the actual delivery, but change into it after my first shower.  It's a cool material and plenty big.  Snaps at the top make nursing in it so easy.  You are well covered for guests to visit.  Pre-pregnancy i'm size 8 and ordered a small (which says sizes 0-10).  It fits great, loose like you want.  As a plus, it's much cuter than the hospital gowns so makes for cute first pictures with your little one.