Final answer:
To stimulate maturation of a preterm baby's lungs, the nurse should anticipate giving betamethasone, a corticosteroid that accelerates lung development and decreases the risk of respiratory distress syndrome in premature infants.
Step-by-step explanation:
In preterm labor, a medication often given to stimulate the maturation of the baby's lungs is betamethasone. Betamethasone is a corticosteroid that helps accelerate the development of the fetus's lungs, reducing the potential risks associated with prematurity such as respiratory distress syndrome. The nurse should expect to administer betamethasone or similar corticosteroids such as dexamethasone for this purpose.
Magnesium sulfate might be used to protect the baby's brain in cases of extreme prematurity and terbutaline may be used to attempt to slow or stop the labor, but for lung maturation specifically, betamethasone is the appropriate medication. Methotrexate is not used for this condition as it is a chemotherapy agent used for ectopic pregnancies and certain cancers.