labor induction was utilized in 22.5% of U.S. births.1 Despite this high rate, and despite the fact that among nulliparas, laborinduction is associated with a doubling of the cesarean rate even after controlling for maternal demographic characteristics, medical risk, and pregnancy complications,2 there is no commonly accepted definition of “failed labor induction.” Specifically, neither of the two major obstetric textbooks currently in use in the United States,3,4 nor the American College of Obstetricians and Gynecologists (ACOG) practice bulletin5 on labor induction includes an explicit definition, although the latter acknowledges that “allowing at least 12–18 hours of latent labor before diagnosing a failed induction may reduce the risk of cesarean delivery.”