There have been some really in depth and passionate threads on MDC about bringing goodies to the hospital (just search, I'm sure you'll find some). They tend to boil down to "bringing food or other gifts for the nurses will make them think well of you, and you'll be more likely to have the birth you want" on the one hand and "bringing food or other gifts for nurses in the attempt to make them think well of you is insulting to their professionalism and could backfire". With the now and then comment about how after a shift change, no one knows who those goodies are from anyway (especially in a large hospital where there may be 20+ women laboring at any given time).
Personally, when I worked at the reference desk, we sometimes had patrons who needed a lot of time and attention (it was a university, we worked with some patrons for well over a year on a topic). When those patrons brought goodies after spending time with us on a project, we were thrilled and yes... we would feel a lot more charitable towards their "emergency" emails and crazy research needs. But I think that if someone approached the desk with a gift "up front", before working with us, we'd have been a bit creeped out and assumed that this patron was going to be difficult and that they didn't think we would treat them well without some sort of bribe. Because of my own experiences, I send food and goodies to the nurses station after the babe is born as a thank you. But not before the birth. I've never had anyone be rude or inconsiderate to my face (and I don't really care what they do/say elsewhere), and if they were I'd be more likely to demand a staff change then offer them a cookie in the hopes that it would improve their blood sugar and/or attitude towards me (don't forget that you're in charge, a staffer can't leave you but you can always send them away... I know one local mom who told her OB to leave her room and she was attended from there on out by the on call OB).
But no matter what you do, if you bring edible goodies make sure to include an ingredient list and if the food was made in any specific way (as in, label it kosher, or from a celiac safe kitchen, or "from the Blah de Blah Bakery", or whatever it may be). And add a card that includes your name and some sort of personal message (even just a "Thank you!") so that after shift change there's a chance that the goodies will still be "credited" to you. :)
And sometimes it's the non-edible goodies that are the best loved and the most noticed (if you want to stand out in the birth crowd)... like little bags with sample sized hand lotions and lip balm, or bookmarks/bumper stickers that reflect their job as birth attendants, or origami birds/flowers with "thank you" written on the wings or leaves, a case of specialty soda or large box of nice coffee. That sort of thing.