Final answer:
Local anesthesia is commonly used during bone marrow aspiration in newborns to prevent pain and discomfort during the procedure.
Step-by-step explanation:
The nurse should explain to the mother that local anesthesia is commonly used during bone marrow aspiration in newborns. Local anesthesia involves numbing only a specific area of the body, allowing the newborn to remain awake during the procedure while preventing pain or discomfort in the area being worked on. This is typically done by injecting a numbing medication into the skin around the site where the bone marrow sample will be taken.