Most fetal heart rate patterns can be interpreted accurately so that management decisions can be made correctly. How-ever, few fetal heart rate patterns are so ambiguous that the obstetricians cannot interpret them precisely. A 27-year-old woman at 38 weeks' gestation in her first pregnancy was admitted with heavy vaginal bleeding and decrease in fetal movements. Fetal status was indeterminate according to an indefinite fetal heart rate tracing with regular decelerations. After emergent cesarean delivery, a ruptured vasa previa, traversing the fetal membrane, unsupported by either the umbilical cord or placental tissue, was clearly identified. Treatment decision-making is challenging in such patient with indefinite fetal heart rate pattern because limited data exist to guide management. Well-designed studies are needed to clarify the uncertainty about the effect of indefinite fetal heart rate pattern on clinical outcomes.
Keywords: Cardiotocography; Cesarean section; Fetal heart rate; Pregnancy; Vasa previa.