Final answer:
The nurse should instruct the parents to check the fontanelle for signs of infection.
Step-by-step explanation:
The nurse should include the instruction to check the fontanelle for signs of infection. The fontanelle is the soft spot on an infant's head where the bones have not yet fused together. It is important to monitor the fontanelle for signs of infection, such as redness, swelling, or discharge, as this can indicate a complication with the ventriculoperitoneal shunt.
Avoiding exposure to sunlight is not directly related to the care of the ventriculoperitoneal shunt. Administering prophylactic antibiotics regularly may not be necessary unless specifically prescribed by the healthcare provider. Placing the infant in a prone position can increase the risk of complications with the shunt and is not recommended.