Final answer:
The medication administered to assist fetal lungs to mature in preterm labor is Betamethasone.
Step-by-step explanation:
The medication administered to a woman in preterm labor to assist the fetal lungs to mature is Betamethasone. Betamethasone is a corticosteroid that helps promote lung development in premature babies. It works by stimulating the production of surfactant, a substance that helps the lungs expand and function properly.