Apnea of prematurity is a pause in breathing that lasts for more than 20 seconds.
Apnea of prematurity commonly occurs in infants who are born preterm, increasing in frequency and severity among the most prematurely born. In these newborns, the part of the brain that controls breathing (respiratory center) has not matured fully. As a result, newborns may have repeated episodes of normal breathing alternating with brief pauses in breathing. In tiny premature newborns, apnea can also be caused by temporary obstruction of the throat (pharynx) due to low muscle tone or a bending forward of the neck (obstructive apnea). Over time, as the respiratory center matures, episodes of apnea become less frequent, and by the time the newborn approaches term, they no longer occur.
Symptoms and Diagnosis
Premature newborns are routinely placed on a monitor that sounds an alarm if the newborn stops breathing for 20 seconds or if the heart rate slows. Depending on the length of the episodes, stoppage of breathing may decrease the oxygen levels in the blood, which results in a bluish discoloration of the skin (cyanosis). Low levels of oxygen in the blood may then slow the heart rate (bradycardia).
Apnea can sometimes be a sign of a disorder, such as infection in the blood (sepsis), low blood sugar (hypoglycemia), or a low body temperature (hypothermia). Therefore, doctors evaluate the newborn to rule out these disorders when there is a sudden or unexpected increase in frequency of apnea episodes. Doctors may obtain specimens of blood, urine, and cerebrospinal fluid to test for serious infections and test blood samples to determine whether the level of sugar is too low (hypoglycemia).
When apnea is noticed, either by observation or monitor alarm, newborns are touched or prodded gently to stimulate breathing, which may be all that is required. Further treatment of apnea depends on the cause. Apnea caused by obstruction of the pharynx may be decreased by keeping newborns lying on their back or side with their head in a centered position. If episodes of apnea become frequent, and especially if newborns have cyanosis, they may be treated with a drug that stimulates the respiratory center, such as caffeine. If this treatment does not prevent frequent and severe episodes of apnea, newborns may need treatment with continuous positive airway pressure (CPAP)—a technique that allows newborns to breathe on their own while receiving slightly pressurized oxygen or air given through prongs placed in the nostrils—or with a ventilator.
Virtually all premature newborns stop having episodes of apnea several weeks before they reach term.
Preterm birth is a risk factor for sudden infant death syndrome (SIDS—see Miscellaneous Disorders in Infants and Young Children: Sudden Infant Death Syndrome (SIDS)), but an association between apnea and a later risk of SIDS has not been proved. Likewise, there is no proof that discharging a premature newborn from the hospital on an apnea monitor decreases the risk of SIDS.
Last full review/revision February 2009 by Arthur E. Kopelman, MD