It is common for premature babies to have breathing that is not as regular as full-term babies. This is called periodic breathing: moments when the time between breaths is longer than what would normally be expected. If these intervals between breaths extend for longer than 20 seconds, the baby is classified as having apnea. At times, these pauses are accompanied by a slowing of the heart rate, which is called bradycardia.
Apnea of prematurity is common; about 80% of premature babies born before 30 weeks of pregnancy will have the condition to some degree. In some ways, it’s not that hard to understand why apnea occurs: a premature baby’s immature brain is not programmed to breathe regularly until 34 weeks of age or later since the placenta is doing all the functions of the lung in the womb.
The apnea usually begins during the first days of a premature baby’s life. The baby may have only one or two episodes a day, or as many as a dozen. As the baby’s brain matures, the condition disappears, usually with no more episodes when the baby’s breathing centre has fully matured, usually around 40 weeks’ gestational age. Parents who are not used to these events can find them quite alarming. However, in most cases, apnea resolves itself with no harm done. The premature baby’s health care providers are usually concerned only when the episodes of apnea are unusually long, the apnea follows an unexpected course, or the apnea appears to be a symptom of some other condition.
Apnea can also be a symptom of other conditions such as low blood sugar or infection, and so the baby may be investigated for those conditions. As these conditions are treated, the apnea will disappear.
Babies in the Neonatal Intensive Care Unit (NICU) have their heart and breathing rates constantly monitored and if an apnea occurs, the baby’s health care providers will be immediately alerted to it. Usually it only takes a small amount of physical stimulation to get the baby to begin regular breathing again. A gentle rub is often sufficient.
Some babies, especially the extremely premature who are more at risk for frequent episodes of apnea, may be given medication to help stimulate them into regular breathing. Caffeine is often used. In small amounts, the kick or stimulus produced by caffeine is usually enough to keep the baby breathing regularly. Some premature babies may require respiratory support for their apnea of prematurity even though they have minimal or no lung disease. The respiratory support may include nasal continuous positive airway pressure (CPAP), or intubation and mechanical ventilation.