What is a characteristic sign of Tetralogy of Fallot in a newborn?

A characteristic sign of Tetralogy of Fallot in a newborn is cyanosis when quiet. This condition is a congenital heart defect that involves four anatomical abnormalities: ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. These structural issues lead to decreased blood flow to the lungs and mixing of oxygen-poor blood with oxygen-rich blood.

In newborns, when they are quiet, there is less physical activity and, consequently, less oxygen demand. However, the inherent defect in blood flow and oxygenation causes pronounced cyanosis during this calm state, as the right-to-left shunt of blood becomes more significant. This cyanosis is a hallmark indicator of the condition and can be an early clinical sign that triggers further evaluation and intervention.

While cyanosis during activity can occur in some cases due to increased oxygen demand, it may not be present in all patients. Consistent respiratory distress is less specific as it can signify a variety of respiratory or cardiac conditions. Finally, immediate need for resuscitation is more acute and may not be a characteristic sign observed in all newborns with Tetralogy of Fallot, especially if they are stable at birth.