If a patient has vasa previa, the most appropriate treatment is:

In cases of vasa previa, the most appropriate treatment is a cesarean delivery. Vasa previa occurs when fetal blood vessels cross or run near the internal cervical os, which poses a risk of vessel rupture during labor. This rupture can result in rapid fetal hemorrhage, endangering the life of the fetus.

A planned cesarean delivery is typically scheduled for around 34 to 36 weeks of gestation, prior to the onset of labor. This proactive approach allows for controlled delivery in an environment where immediate medical intervention can be performed if necessary, thereby minimizing risk to the fetus. The urgency stems from the fact that labor contractions can disrupt the fragile fetal blood vessels, leading to serious complications.

The other options would not provide the necessary safety measures for the fetus. A vaginal delivery or a carefully monitored vaginal birth could lead to significant risks associated with potential vessel rupture. Administering steroids is typically intended for promoting fetal lung maturity in cases of preterm delivery but does not address the immediate dangers posed by vasa previa itself. Thus, cesarean delivery is the preferred and safest course of action in this situation.