Sudden infant death syndrome (SIDS) occurs when a healthy baby under the age of 1 dies suddenly and unexpectedly. Healthcare professionals are unsure why SIDS happens. However, certain factors can put a baby at risk of SIDS.

SIDS is the most commonTrusted Source cause of death in infants less than 1 year of age in the United States.

Taking steps to reduce risk factors, such as following safe sleep recommendations for infants, may help prevent SIDS.

Keep reading to learn more about the causes, risk factors, and prevention tips. This article also looks at the support options that are available.

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When a healthy baby under the age of 1 dies, and a thorough clinical investigation is unable to find the cause of death, a doctor may diagnose SIDS. SIDS has no warning signs or visible symptoms.

According to the National Institute of Child Health and Human Development (NICHD)Trusted Source, SIDS is the sudden, unexpected death of a healthy infant under the age of 1.

The NICHD notes that 90%Trusted Source of SIDS deaths occur before the infant reaches 6 months of age, but it may happen anytime during the infant’s first year of life. It is unlikely to occur after this period.

According to the Centers for Disease Control and Prevention (CDC)Trusted Source, 1,250 infants died of SIDS in the United States in 2019. This translates to approximately 33 in 100,000 live births.

Researchers do not know why SIDS occurs, but they have identified some potential factors.

According to health expertsTrusted Source, a combination of factors may increase a baby’s chance of SIDS.

Physical factors

Some physical factors linked with SIDS include:

  • Brain development: ResearchTrusted Source suggests that infants who die from SIDS may have an abnormality in the brain centers that control breathing and sleep arousal.
  • Low birth weight: SIDS risk is higher for infants with low birth weights. Research from 2014 states that the risk of SIDS is four times more likely for those who are born with a low birth weight or those born prematurely. The higher risk may be due toTrusted Source the fact that the respiratory system is underdeveloped.
  • Respiratory infections: Research indicates respiratory infections are involved in some SIDS cases. A person should speak with a doctor, such as a pediatrician, if a baby has a respiratory infection or is experiencing any worsening symptoms.

Sleep environmental factors

A baby’s sleeping position and sleep environment can impact physical factors that may increase their risk of SIDS. These includeTrusted Source:

  • Sharing a bed: While caregivers sharing a room with the baby may reduce the risk of SIDS by 50%Trusted Source, caregivers, siblings, or pets sharing a bed with a baby can increase the risk.
  • Sleeping on a soft surface: Sleeping on soft surfaces, such as loose beddings, can block breathing and cause suffocation in infants.
  • Sleeping on the side or stomach: Sleeping in either position can cause breathing difficulty in infants, and doctors do not recommend it.
  • Overheating: Excessive clothing, covering the baby with a blanket, or sleeping in a room with a high temperature can cause the baby to become too hot and may increase the risk of SIDS.

While there is no known cause of SIDS, the following factors can increase a baby’s risk:

There appears to a higher incidenceTrusted Source of SIDS in African American and Indigenous populations.

According to a 2018 reviewTrusted Source, Black women may be less likely to follow safe sleeping practices due to cultural beliefs.

A 2019 studyTrusted Source suggests that African American mothers did not follow Safe to Sleep recommendations due to finding them unnecessary, not feeling comfortable doing so, or feeling unable to do so.

However, it is important to note that there is a disparity in the amount of research that goes into investigating health conditions in Communities of Color.

There may be other reasons why the rate of SIDS is high in the Black community than the ones researchers have found, such as a distrust of healthcare professionals as a result of systemic racism, or not having the same access to healthcare.

Prenatal risk factors

Some prenatal factors can also place an infant at high risk of SIDS. These factors include:

  • teenage pregnancy
  • poor prenatal care
  • multiple births within short intervals of less than 1 year apart
  • a history of alcohol, drug use, or cigarette smoking during pregnancy and after birth

SIDS may not be preventable in some cases. However, following risk reduction strategies can help reduce its likelihood.

People should always ensure that they place the baby on its back to sleep, for both naps and during the night.

The NICHDTrusted Source notes that if a baby rolls over by themselves, a person does not need to reposition them. The act of starting sleep on their back is the important part of reducing the risk of SIDS.

In addition, people should use a firm and flat sleeping mattress. People should also use a safety-approved crib, covered only by a fitted sheet. People should remove all soft toys and other soft items from the crib.

In addition, the American Academy of Pediatrics (AAP) recommends that people:

  • practice room-sharing without bed-sharing
  • keep the baby’s crib as bare as possible
  • keep soft objects away from the baby’s sleep area
  • breastfeed the baby, if possible, for the first 6 months
  • use a pacifier, but do not force it if the baby is uninterested
  • get early and regular prenatal care during pregnancy
  • get the recommended immunization shots for the baby

People should avoid:

  • over-wrapping to prevent the baby from getting too warm
  • smoke exposures during pregnancy and after birth
  • drinking alcohol and using recreational drugs during pregnancy and after birth

When it comes to the best sleeping position for babies in their first year of life, the AAP recommends sleeping on the back as the safest. Infants who sleep on their backs seem to have a lower risk of SIDS.

This may be because sleeping on the back opens up the airways and reduces any chance of suffocation that may arise from a poor sleeping position.

Some people are concerned that the baby may choke on saliva or vomit when sleeping on their back, but the NICHDTrusted Source states that babies who sleep on their back may clear fluids better.

Another concern caregivers may have is that sleeping on the back can cause a flat head and back. However, these effects are usually temporary and will normalize when the baby turns 1 year old. Observing supervised “tummy times,” where the baby lies and plays on their tummy while awake, may helpTrusted Source reduce these.

Sleeping on the stomach is unsafe for infants because it can increaseTrusted Source their risk of dying from SIDS. This sleeping position can block the airways, making it difficult for the infant to breathe.

Also, the chance of the baby rebreathing exhaled air is higher. This may also lead to SIDS. In another instance, the baby may breathe in germs from the mattress cover, which can cause allergies.

For these reasons, the AAP recommends – as outlined in the Safe to Sleep campaignTrusted Source – that caregivers place all infants under 1 year of age on their backs to sleep.

Experiencing a SIDS death can be overwhelming. It is common for people to experience different emotions that can affect their health and well-being.

The following are support groups for people who have lost a child to SIDS:

SIDS is a condition that occurs when a healthy infant less than 1 year of age dies suddenly and unexpectedly.

While the cause of SIDS is unclear, following the approved safety guidelines may help reduce its risk factors.

For people who experience SIDS death, many resources are available to provide support and help them navigate the grief that comes with this traumatic event.