A nurse is caring for a newborn who has macrosomia and whose mother has diabetes mellitus. The nurse should recognize which of the following newborn complications as the priority focus of care?

A. Hypomagnesemia can occur in newborns of diabetic mothers but is less immediate and not the primary concern. B. Hypocalcemia is a possible complication but usually develops after the first 24–48 hours; it is important but not the first priority. C. Hypoglycemia is the most immediate and critical risk in newborns of diabetic mothers due to hyperinsulinemia from maternal hyperglycemia. It can lead to seizures, brain injury, or death if not promptly recognized and treated. The nurse should monitor blood glucose closely and intervene quickly. D. Hyperbilirubinemia may occur later, often due to polycythemia or prematurity, but it is not the immediate priority in the immediate neonatal period compared with hypoglycemia.