It's not uncommon for sleeping babies to go for a few seconds without breathing, but the condition can be much more severe in premature infants. That's because the area of the brain that controls breath isn't fully mature. When a baby stops breathing for 15 to 20 seconds at a time, he or she is usually diagnosed with apnea of prematurity (AOP).
During an instance of apnea, the baby's heart rate will decrease and the skin will turn pale or blue. Newborn preemies are usually hooked up to a monitor that will alert caregivers if the baby stops breathing for a certain number of seconds. You can usually get the baby to breathe again simply by rubbing his or her back, arms or legs, but some preemies may require time on a ventilator or medications. AOP usually goes away on its own, and doctors don't think it causes any long-term brain damage.