What is the most common type of apnea in the preterm infant?

• A. Central apnea
• B. Obstructive apnea
• C. Sleep apnea
• D. Mixed apnea

Answer: (D)

In preterm infants, apnea of prematurity typically presents as mixed apnea. This pattern reflects two immature systems at once: the brain’s control of breathing is not fully developed, so there can be pauses in respiratory effort (central component), and the upper airway is often lenient and prone to collapse during those pauses (obstructive component). Many events start with reduced or absent respiratory effort and then become obstructed as the airway collapses, leading to a combined, or mixed, apnea. Central apnea alone is less common in this population, and true obstructive apnea without any central component is also less typical. Recognizing mixed apnea helps explain why these episodes are often associated with desaturation and bradycardia and why therapies that support both central drive (for example, caffeine citrate) and airway patency (such as nasal CPAP) are used in management.