What is Infant Apnea?
Apnea in babies refers to periods when they stop breathing for a moment. These stops can have different causes, both natural and potentially harmful. For example, it’s normal for babies aged between two and four weeks to stop breathing for 5 to 10 seconds at a time – this is called periodic breathing and usually stops by the time they are six months old.
While it’s more common in premature babies, any baby can experience apnea. There are two specific types of apnea based on the age. ‘Apnea of prematurity’ is when a premature baby (younger than 37 weeks) stops breathing for at least 20 seconds, or if they have a slow heart rate (bradycardia) or a lack of oxygen (cyanosis). ‘Apnea of infancy’ refers to any unexplained instance where an infant stops breathing for 20 seconds or more, or a shorter pause in breathing that is paired with bradycardia, cyanosis, paleness, and/or severe limpness (hypotonia).
There are three types of apnea: central, obstructive, and mixed. Central apnea happens when the part of the brain that controls breathing is not working properly, leading to no effort to breathe. Obstructive apnea happens when something blocks the baby’s airways, resulting in the baby’s efforts to breathe not being enough to maintain proper air flow. Mixed apnea, which happens most frequently in premature babies, includes both a period of central apnea followed by airway obstruction.
What Causes Infant Apnea?
Breathing pauses, or apnea, in babies, can happen for many different reasons, and these reasons can be influenced by the baby’s age and underlying physical conditions.
Preterm babies, especially ones born earlier than 28 weeks, are more likely to experience apnea due to underdeveloped respiratory control systems. This condition is known as ‘apnea of prematurity’.
Apnea can also happen shortly after birth because of issues like lack of oxygen during birth, drugs used by the mother, infections, metabolic causes, or birth abnormalities.
Central apnea, a type of apnea associated with the brain’s control of breathing, can result from brain infections such as meningitis and encephalitis. Other potential causes could be head trauma, exposure to harmful substances, whooping cough (pertussis), certain muscle-related diseases, metabolic abnormalities such as low blood sugar or calcium, and certain birth defects. This includes conditions like Down syndrome and Arnold-Chiari malformation, a condition affecting the area where the brain and spinal cord meet.
Obstructive apnea, a condition where breathing stops periodically during sleep because of blocked airways, can happen due to infections like pneumonia, whooping cough, paralysis of the vocal cords, or congenital airway abnormalities, such as Pierre-Robin sequence, a condition present at birth, characterized by a smaller-than-normal lower jaw.
Mixed apnea, which is a combination of central and obstructive apneas, mainly occurs in premature infants. However, other conditions such as acid reflux, whooping cough, and inflamed small air passages in the lungs can also cause it.
Risk Factors and Frequency for Infant Apnea
The actual number of cases and frequency of apnea in babies, especially preterm or premature infants, is not well known. What we do know is that apnea, a temporary stop in breathing, is more common in babies born very early. Almost all babies born before they’ve completed 28 weeks of development in the womb experience episodes of apnea. For babies born between 33 to 34 weeks, about half of them experience it. As for babies who complete the full term of pregnancy (known as full-term infants), apnea occurs in about one in every thousand.
Signs and Symptoms of Infant Apnea
When investigating incidents of apnea, or stoppages of breathing, it’s critical to determine if they are real apneic episodes or just periodic breathing or breath-holding spells. A comprehensive review of the baby’s history before birth, during delivery, after birth, and their feeding habits should be done if it’s a real apnea. The presence of repeated apneic episodes is a strong indicator of a severe underlying issue and increases the chances of it happening again.
It’s important to inquire about any family history of seizures or infant deaths, and if any serious illnesses run in the family. Living conditions, exposure to toxins such as medications, tobacco smoke, or carbon monoxide should also be considered. Other related symptoms like sleep disturbances, snoring, and mouth breathing are important to note too.
A physical examination can provide important information, helping to identify birth defects, genetic conditions, metabolism disorders, or infections present from birth. Fever or low body temperature could suggest sepsis or other infections,
- Fast breathing might be due to a lower respiratory tract infection or a metabolic imbalance causing your blood to become too acidic,
- Stridor, or noisy breathing, could suggest a blockage in the upper airway,
- Unexplained skin bruises might mean the child has been mistreated.
Testing for Infant Apnea
When examining a newborn baby, the doctor will typically conduct a thorough review of the baby’s health history and conduct a physical exam. If needed, they might suggest conducting certain tests such as a complete blood count to evaluate the baby’s overall health, as well as checking levels of serum glucose, calcium, and electrolytes in the blood.
If the baby has a fever or unusually low body temperature and the doctor suspects a severe infection, they may take samples for cultures of blood, urine, and possibly cerebrospinal fluid (the fluid around the brain and spinal cord). Cultures can help identify the specific bacteria or other organisms causing an infection. An EKG (a test that measures the electrical activity of the heartbeat) may be performed to rule out any heart rhythm disorders, like Long QT syndrome, which is a heart rhythm condition that can potentially cause fast, chaotic heartbeats.
Additionally, advanced tests like neuroimaging (brain scans), EEG (a test that detects electrical activity in the brain), or specialist consultations are not usually recommended unless the baby’s symptoms specifically indicate the need. If the baby has experienced a Brief Resolved Unexplained Event (BRUE), which is a sudden, brief, and now resolved episode in an infant that is frightening to the observer, and the baby is considered low-risk, no further lab tests are typically required.
Treatment Options for Infant Apnea
The first step doctors take when an infant experiences apnea (or stops breathing) is to figure out whether the baby requires instant medical help or stabilizing. The next step is to figure out what’s causing the apnea and to start treatment for that particular cause. For newborns, it’s advised that they are observed in the Neonatal Intensive Care Unit (NICU), where their heart and breathing rates, as well as their oxygen levels, can be monitored.
When the apnea is a result of being preterm, certain actions are suggested if the apnea events happen often, last too long, need regular stimulation, or come with slow heart rate or low oxygen levels. These babies may be helped by nasal continuous positive airway pressure (CPAP), which helps keep their airways open, or methylxanthine treatment, that can stimulate their breathing. But studies have not shown methylxanthine to be effective for babies who were born full-term (not premature).
Therapists who specialise in speech or physical tasks may also be called in if the baby has issues related to eating. If babies fall in the lower-risk category of Brief Resolved Unexplained Events (BRUE), where they exhibit puzzling short and resolved symptoms, the best course of action is usually to reassure and educate parents.
What else can Infant Apnea be?
The following are different medical conditions that could be under consideration for a diagnosis:
- Aspiration syndrome
- Bacteremia (bacteria in the blood)
- Botulism (rare type of food poisoning)
- Bronchiolitis (inflammation of the bronchioles)
- Bronchopulmonary dysplasia (lung condition affecting newborns)
- Childhood sleep apnea (breathing disorder during sleep)
- Croup (respiratory infection)
- Congestive heart failure
- Influenza (flu)
- Laryngomalacia (softening of the larynx)
- Munchausen syndrome by proxy (psychological issue where a caregiver makes up or causes illness in a person under their care)
