What finding would suggest respiratory distress in a newborn?

Stridor is a specific finding that suggests respiratory distress in a newborn due to its association with upper airway obstruction or narrowing, such as might occur with conditions like croup or laryngomalacia. In this scenario, the presence of stridor indicates that the airway is partially obstructed, leading to a high-pitched wheezing sound when the infant inhales. This is a critical sign warranting immediate medical evaluation, as it can lead to more severe respiratory compromise if not addressed promptly.

Quiet breathing typically suggests normal respiratory function, while lethargy could point to other medical issues but is not specific to respiratory distress. Hyperactivity is not a common indicator of respiratory distress in infants; rather, a distressed newborn may be less active or more irritable. Therefore, stridor stands out as a clear and direct indicator of potential respiratory distress in newborns, necessitating further investigation.