What is the most common cause of congenital stridor in infants?

Congenital stridor in infants is most commonly associated with laryngomalacia. Laryngomalacia is characterized by soft, floppy tissue above the vocal cords, which can collapse inward during inhalation, leading to noisy breathing or stridor, especially when the infant is supine or during crying. It typically presents within the first few weeks of life and is often a benign condition that resolves as the child grows and the cartilage matures, usually by the age of 18 months to 2 years.

This condition is the leading cause of stridor in infants, often characterized by the distinctive "sounds" it produces, which are described as a high-pitched, squeaky noise during breathing. While other conditions can cause stridor, laryngomalacia is by far the most prevalent cause in the pediatric population and is usually diagnosed clinically with a characteristic history and examination findings.

In contrast, vascular ring and tracheomalacia can cause stridor but are less common as causes of congenital stridor. Recurrent respiratory infections may lead to stridor due to inflammation or other complications but are not a congenital cause. Therefore, laryngomalacia stands out as the most common etiology for congenital stridor in infants.