Summary![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Sudden infant death syndrome (SIDS) is the abrupt and unexplained death of an infant less than 1 year old. Although the etiology of SIDS remains unclear, evidence suggests that it is caused by a combination of environmental triggers and cardiorespiratory impairment, which then leads to prolonged hypoxia. Most cases of SIDS occur in the first 6 months of life. Parents should receive information on how to prevent SIDS during prenatal care and in pediatric check-ups after birth. Recommendations include placing the infant on their back to sleep, ensuring a safe sleep environment (e.g., appropriate sleeping surface and sleepwear, room-sharing with a caretaker, avoiding accessories like pillows and toys) avoiding overheating, and avoiding second-hand smoke. SIDS is a diagnosis of exclusion, and autopsy is required to rule out other causes of death (e.g., congenital cardiac anomalies or battered child syndrome).
Epidemiology![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Etiology![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
The etiology of SIDS remains unclear. Evidence suggests that it is caused by a combination of both extrinsic and intrinsic factors, which ultimately lead to acute or chronic hypoxia. Over 90% of cases of SIDS occur during sleep. [3][4]
Extrinsic factors [4][5]
- Sleeping in the prone position
- Exposure to nicotine during pregnancy and after birth (including 2nd-hand smoking)
- Young maternal age (especially < 20 years)
- Overheating
- Unsafe sleeping environment or CO2 rebreathing, e.g., a shared blanket, stuffed animals in the crib, soft bedding
Intrinsic factors [3]
- Male sex
- Prematurity
- Prenatal and/or postnatal exposure to smoking, alcohol, and/or drugs
- Polymorphisms in the serotoninergic pathway
- Brainstem abnormality that affects serotoninergic modulation of cardiorespiratory control and impairs protective responses to external stressors
Differential diagnoses![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
SIDS is a diagnosis of exclusion. As with any unexplained infant death, US law requires an autopsy to rule out other causes of death.
- Congenital anomalies (e.g., cardiac anomalies)
- Fatal child abuse
- Intentional suffocation
- Battered child syndrome
- Closed head injury
- Poisoning
- Metabolic disease (e.g., MCAD deficiency)
- Infections (e.g., pneumonia, meningitis, sepsis)
- Aspiration, asphyxiation
- Anaphylaxis
- Hyperthermia
- Epilepsy
The differential diagnoses listed here are not exhaustive.
Brief resolved unexplained event (BRUE; formerly apparent life-threatening event, ALTE)![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Definition: a sudden, brief (< 1 minute), and resolved event without apparent cause occurring in a child < 1 year and involving ≥ 1 of the following:
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Risk stratification
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The presence of all the following criteria indicates a low risk of adverse outcomes, recurrence, and serious underlying conditions:
- Age > 60 days
- Gestational age ≥ 32 weeks and corrected gestational age ≥ 45 weeks
- Event lasted < 1 minute
- First BRUE
- No CPR by a trained medical provider required
- No concerning signs or symptoms on physical examination (e.g., bruising, choking, coughing)
- No concerning history (e.g., feeding problems, apneas)
- Patients who do not meet all of the criteria should be considered at high risk for adverse outcomes, recurrence, and serious underlying conditions.
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The presence of all the following criteria indicates a low risk of adverse outcomes, recurrence, and serious underlying conditions:
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Diagnosis
- Physical examination and history
- Diagnosis of exclusion: If a cause for the event can be determined, then it is not BRUE.
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Management
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Patients with low-risk BRUE [6]
- Education for caregivers
- Recommend CPR training to caregivers
- Patients with high-risk BRUE [7]
- Initial evaluation and management
- Monitoring: continuous pulse oximetry for at least 4 hours
- Consultation: screen for child abuse, mental health factors, and feeding evaluation
- Diagnostic testing for potential underlying causes
- Concern for child maltreatment: consultation with child abuse expert, head imaging, skeletal survey
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Secondary evaluation and management
- If no cause can be established after primary evaluation, hospital admission for continuous prolonged oximetry, observation, swallow evaluation, and feeding consultation is indicated.
- Further interventions according to event characteristics
- Initial evaluation and management
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Patients with low-risk BRUE [6]
Prevention![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Prenatal and well-child care visits should involve education on how to prevent SIDS.
During pregnancy
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No smoking, alcohol, or recreational drugs [8]
- Prenatal care
Protective factors after birth
- The infant should be placed to sleep in the supine position
- Safe sleep environment: firm mattress, no pillows, blankets, stuffed animals, or bumper pads in the crib. [9][10]
- In the first 6 months, co-sleeping in the same room without bed-sharing [11]
- Smoke-free environment
- Avoid overheating
- Use of pacifier during sleep, especially between 1 and 6 months of age [12]
- Breastfeeding until at least the age of 4 months [13]
- Placing an infant in a prone position while awake and supervised (tummy time) helps strengthen neck and shoulder muscles.
- Immunization in line with the official vaccination schedule to prevent infections associated with SIDS