Apnea is a pause in breathing for 20 seconds or more. Premature infants younger than 32 to 34 weeks' gestational age commonly have apneic spells, usually while sleeping. During an apneic spell, an infant's blood oxygen level can drop (oxygen desaturation, or "desat"), which is sometimes followed by a drop in heart rate (bradycardia).

The cause of apnea of prematurity is poorly understood. It is known to be related to the infant's immature neurological, muscular, and respiratory development.

Until about 34 weeks' gestation, premature infants are electronically monitored for apnea and bradycardia spells, as well as for desaturation. Apnea spells generally stop around the time an infant is able to have all feedings by nipple, rather than tube. This is usually between 34 and 38 weeks, though it can take longer. Preemies born extremely early, between 24 and 28 weeks, are more likely to have apnea beyond their due dates. A few have apnea for several months. After apnea spells have stopped for a week or more, they usually do not recur.¹

Severe apnea is usually treated with medicine, breathing support, or both. Common treatments include:

• Caffeine or theophylline, an asthma medicine that controls inflammation in the airways of the lungs. Either medicine is a proven treatment for apnea and is usually given for 2 weeks, or until 32 to 34 weeks' gestational age. When medicine is stopped, the infant continues to be monitored for apnea spells for a period of time.
• Oxygen therapy, continuous positive airway pressure (CPAP), or assisted ventilation, to reduce the effects of apneic spells.