Final answer:
The nurse anticipates that the first concern for the mother of a preterm newborn in the NICU is fatigue.
Step-by-step explanation:
The first concern that the nurse anticipates for the mother of a preterm newborn placed in the neonatal intensive care unit is fatigue. Giving birth to a preterm baby can be physically and emotionally exhausting, and the mother may have gone through a long and challenging labor. Additionally, caring for a newborn in the NICU requires frequent visits and monitoring, which can further contribute to fatigue.