Once born, the baby needs to breathe continuously to get oxygen. The brain controls the breathing rate and rhythm. The premature baby's brain is not yet programmed for nonstop breathing and so the baby sometimes stops breathing. Apnea caused by an immature brain is called central apnea. The premature baby outgrows central apnea as the brain matures.
Premature infants have another kind of apnea spell called obstructive apnea.
This kind of apnea occurs when their fragile airway is blocked. The block may be caused by mucous, or the baby may be in a position that kinks the airway. The baby tries to breathe but can't move air because of the blockage. Suctioning the airway or changing the baby's position usually relieves the problem. Again, growth and strengthening of the tissues in the airway solve this problem.