Final answer:
The nurse understands that the administration of betamethasone was effective when observing an increased newborn respiratory rate, indicating improved lung function essential for the survival of a preterm baby.
Step-by-step explanation:
A nurse administered 2 doses of betamethasone to a client in preterm labor. After delivery of the newborn, the nurse understands the medication was effective when she observes increased newborn respiratory rate. Betamethasone is a corticosteroid that is given to pregnant women at risk of preterm delivery to help accelerate the development of the fetus's lungs. An increase in the newborn's respiratory rate indicates improved lung function and a greater ability to breathe effectively outside the womb. This is crucial for the survival and health of a preterm baby as undeveloped lungs can lead to respiratory distress syndrome and other complications.