Apnea and Bradycardia:

• Apnea: pauses in breathing for several seconds that can cause your baby to appear pale or blue as oxygen level drops.
• Bradycardia: slowing of the heart rate.
• Babies with apnea may become limp and bradycardic.
• When the part of the brain that controls breathing is not fully developed, apnea and bradycardia may result. This means these two conditions are more common in ELBW and VLBW premature babies.
• As premature babies age, apnea improves and disappears.
• Treatments for apnea involve:
  • Stimulating the baby
  • Giving daily caffeine which prevents apnea
  • Giving continuous positive airway pressure at the nose to keep the air passages open, with a CPAP machine
• Apnea in premature babies in NICU does not cause brain damage and typically resolves by the time they reach 40 weeks gestation.

Reference: 

AbbVie Corporation (Ed.). (2015). Preemie Parent Handbook (4th ed.). Canada: AbbVie Corportation.