Which is the most common cause of congenital stridor in newborns?

• A. Congenital subglottic stenosis
• B. Laryngomalacia
• C. Laryngeal web
• D. Tracheomalacia

Answer: (B)

Laryngomalacia is the most common cause of congenital stridor in newborns. It happens because the soft tissues above the vocal cords are immature and tend to collapse inward during inspiration, narrowing the airway and creating a high-pitched inspiratory sound. This stridor often appears in the first weeks of life and is typically worse with feeding, agitation, or when the infant is lying on their back, and it usually improves as the airway matures over the first year, often resolving by 12–18 months.

Other conditions can cause stridor but are less common and have distinguishing features: congenital subglottic stenosis tends to cause persistent noise and can be associated with difficulty feeding; a laryngeal web causes stridor with hoarseness due to a fixed obstruction at the glottis; and tracheomalacia usually produces expiratory or biphasic noise from dynamic airway collapse.