Apnea and Bradycardia in Newborns

Some newborns may experience apnea, which is the medical term for an unusually long pause in breathing. This may lead to bradycardia, or a decreased heart rate. Medical professionals often refer to apnea and bradycardia combined as “As and Bs.”

Apnea and bradycardia most often occur in premature babies, because their organs are not yet fully developed. Newborns with apnea and bradycardia often require careful medical supervision and management during early infancy.

Apnea occurs when a baby stops breathing for more than 20 seconds. During a period of apnea, the baby’s heart rate may slow, and in severe cases they may begin to look pale or blue (1). Apnea is far more common during sleep, and especially during the REM cycle (the period during which a baby has rapid eye movement) (2).

Bradycardia describes an unusually slow heart rate. In general, babies have faster heart rates than adults, and premature babies have faster heart rates than term babies. Therefore, a heart rate that is considered normal for an adult may be cause for concern in a newborn (1).

Apnea and bradycardia  may be caused by prematurity, as a result of an underdeveloped nervous system. If the brain’s respiratory center (which sends signals to the lungs to take breaths) is immature, the baby may stop breathing. This is called central apnea (2). Of babies weighing less than 5.5 pounds, about 45% will experience some apnea. For babies weighing less than 2.5 pounds, the rate of apnea jumps up to 85%.

The following are some additional causes of apnea and bradycardia. Premature babies are also more vulnerable to many of these issues:

• Infection
• Baby being overheated, cold, or over-stimulated
• Low blood oxygen (apnea and other breathing problems are common in babies with hypoxic-ischemic encephalopathy (HIE), a form of neonatal brain damage caused by oxygen deprivation)
• Airway obstructions, such as mucous (1). This is known as obstructive apnea (2).
• Neurological issues (1)
• Brain bleeds or tissue damage
• Heart or blood vessel issues
• Feeding tubes or suctioning
• Baby’s neck is too flexed (2)

If a baby is at risk for apnea and bradycardia (for example, if they are premature), they should be placed on monitors to detect their breathing and heart rates. These monitors can alert medical staff if the baby is experiencing apnea or bradycardia. Sometimes the alarms may simply indicate a loose wire or another issue unrelated to the baby’s health, but they serve as an indication that the baby should be checked. Staff will observe the baby’s breathing, heart rate, and coloration (1).

Medical professionals may conduct certain diagnostic procedures in order to determine if apnea is due mainly to prematurity or other causes, as well as evaluate the severity of the issue. These procedures may include:

• Physical examination
• Blood tests
• Nasal swabs (to check for viral infections)
• X-rays
• Apnea study to measure breathing, heart rate, and oxygenation (2)

Babies with apnea and bradycardia often restart breathing without help, but in some cases they may need to be ‘reminded’ to start breathing. Often, hospital staff can achieve this by gently rubbing or stimulating the baby. If the baby’s coloration looks abnormal (e.g. blue), extra oxygen or positive pressure ventilation may be necessary (1).

In some cases, other treatments may be needed. These include:

• Medications such as caffeine or theophylline, which are used to stimulate the central nervous system
• Continuous positive airway pressure (CPAP) applied to the baby’s airways in order to keep them open
• Ventilation or a breathing machine
• Treatment for underlying issues, such as infection (1, 2)

Many premature babies “outgrow” apnea when they reach what would have been about 36 weeks of gestation. This is due to the maturing of their central nervous system.

For babies who are still at risk for apnea and bradycardia after discharge, medical professionals may recommend a home apnea monitor, and that parents follow up with an apnea center or physician qualified to read the monitor downloads. Some parents may also opt to take infant CPR classes.

Apnea is a separate issue from sudden infant death syndrome (SIDS), but babies who experience apnea and require a NICU stay may have a slightly higher risk of later developing SIDS. To prevent SIDS, babies should be placed on their backs for sleeping, and should not have soft mattresses or pillows (1, 3). For more detailed information on how to reduce the risk of SIDS, please click here.

If apnea and bradycardia are properly managed by medical professionals, there may be no long-term negative effects. If apnea and bradycardia are more severe and they’re not promptly addressed, they may result in brain damage and even death.