Intensive care babies have one nurse to two babies, they are generally on some sort of breathing support.
Special Care babies have one nurse to 5-6 babies.
The babies start off being one on one and as they get better it can go to more babies. The most a RN would have in a NICU is 4 babies! Can you imagine what its like to have 4 babies due to be fed at the same time hehe!

The most i have ever had on my own in a SCN is 4 and as a professional i would nurse any more than that. It depends on if you are in a state or private hospital as to the guide lines!