Final answer:
Betamethasone (Celestone) is given to accelerate fetal lung maturity, reducing the risk of respiratory distress syndrome (RDS) in premature infants.
Step-by-step explanation:
The nurse should tell the client that the medication is given to accelerate fetal lung maturity. Betamethasone (Celestone) is a corticosteroid medication that is used to speed up the development of the baby's lungs, reducing the risk of respiratory distress syndrome (RDS) in premature infants. It helps the baby's lungs produce surfactant, which is a substance that keeps the air sacs in the lungs from collapsing.