Internationally, "Marked Variability" has had numerous definitions and interpretations through the years. Growing evidence suggests that increased fetal heart rate variability should be distinguished from moderate variability and may be an indicator for early-stage intrapartum hypoxemia, leading to an increased risk for fetal acidemia and early neonatal complications. What should one do when marked variability shows its rare but confusing presence? Come explore the history, pathophysiology and best practice recommendations for managing Marked Variability.