We don't really care what they're eating with, so long as they're eating. For preemies on the unit, if the free Similac nipples and nuks are too fast, we use Gerber slow flow nipples and nuks. We used to use the Gerber preemie bottles and nipples, which are a lot smaller, but it got to be too expensive. Now if babies have REALLY small mouths, we'll ask their parents to bring in a pack of those. Similac used to make a pink preemie nipple, and I have no idea why they stopped! Some people have said their red nipples are preemie, but I thought the red ones are high flow!
If the kids go home with slow flow or preemie nipples, we give the parents guidelines as to when to change them to the regular ones (less sloppy, no A&B's with feedings, good pacing, etc.) and they usually do just fine. Most of the kids who go home PO ad lib are using regular nipples anyway. It's the babies who go home with NGs that are still using preemie and slow flow ones, and they get home care visits from our RNs so they will transition them to regular nipples at home then.