They have now filed an appeal in a higher court, sources said.
The defence hearing in the case is scheduled for today, the sources said.
In the view of the Oslo district court, the couple had "deliberately burned their son's leg with a hot spoon or similar object with the result that the child had burn marks measuring approximately 3 x 5 centimetres."
The court had said it had been proven that on one occasion the parents had even threatened to brand their son's tongue with a hot spoon.
The jail terms of 18 months for the father and 15 months for the mother were proposed by the prosecution.