Ok, I get what you were saying. We usually use IV fluids where I work on babies who are under photo and want to breastfeed because of the anti-nipple theories and because it's just hard to get some of these babies to eat well and stay under the lights at the same time

Dehydrated, jaundiced babies have to be the worst feeders out there!
I have seen problems with post-partum nurses assessing jaundice/dehydration before and it's led me to be more welcoming of IVs than I was when I was a pp nurse. If a baby is jaundiced enough to require intensive photo, they are at risk for dehydration.