When i had Kimberley we where in hospital a week until she was allowed home. I was not on a ward after day 4 i was in a room with Kimberley in the special baby unit.
With Alexander we where home on the morning of day 5.

I think it all depends on the hospital.
With Kimberley they would not let her go home until she put weight on this time with being a different hospital they did not worry if Alexander had put weight on before sending him home.