SIDS and SUID: Keep Your Sleeping Baby Safe

Neve Spicer
Written by Neve Spicer Updated on November 3rd, 2021

There is strong scientific evidence that following a few simple steps can reduce the chance of Sudden Infant Death Syndrome (SIDS).

In this guide, we present the latest information about infant sleep, along with actionable ‘best practice’ sleep advice from leading pediatricians.

Safer sleep guidelines can provide you with peace of mind during this precious time.

The Infographic

SIDS and SUID- A Guide for Parents (Infographic)

What is Sudden Infant Death Syndrome (SIDS)?

When an infant tragically passes away during their sleep, the immediate and understandable urge of parents and doctors is to identify the cause.

Accidental asphyxiation caused by smothering or suffocating, an undiagnosed metabolic disorder, or a hidden infection are all risk factors for infant mortality.

However, when the cause of death of a child that is less than 12 months old remains unknown, it is generally classified as Sudden Infant Death Syndrome (SIDS).

SIDS is fairly rare, and, as new science informs baby sleep recommendations, the number of cases is, thankfully, falling.

Worldwide, SIDS accounted for about 15,000 infant deaths in 2013, down from 22,000 during 1990. In the US, SIDS counted for nearly 1,500 deaths that year.

The most common age at which SIDS occurs is between 2 to 4 months, with more than 90 percent of SIDS deaths occurring in children less than 6 months old.

SIDS occurs slightly more often in male infants than in females.
Sadly, the number of infant deaths occurring in American homes is all too high — an average of 3,600 infants die yearly in the United States. 1Sudden Unexpected Infant Death and Sudden Infant Death Syndrome – CDC

While the Back To Sleep campaign has been an effective educational outreach, shrinking US infant mortality by two-thirds since 1994, not all parents are fully aware of the precautions to take in order to reduce the risk of this tragedy.

What Is SUID?

SUID is another acronym often seen while researching SIDS, though its meaning is a bit less specific. The CDC coined the term SUID, or Sudden Unexplained Infant Death, for use as a broad term encompassing all sudden deaths in infants.

This means that SIDS, sudden natural deaths, accidental deaths, and homicides all fall under the umbrella term of SUID, as per the CDC.

It is important to note, however, that this is not always how the term is used. In some cases, if a medical examiner performs a thorough post-mortem examination but cannot make an official ruling as to whether SIDS or accidental suffocation was the cause of death, the term SUID is sometimes used.

Because this distinction is virtually impossible to make without examining the scene in which the tragedy occurred, it is becoming more common for investigators to stage in-home reenactments of events to identify the true cause and thus avoid using this umbrella term inappropriately.

Suffocation is a leading cause of infant death. According to the American Academy of Pediatrics, 14 percent of SUID cases are attributed to suffocation.2Sleep-Related Infant Suffocation Deaths Attributable to Soft Bedding, Overlay, and Wedging – AAP

There are three main causes of infant suffocation: soft bedding, usually in adult beds (69%), overlaying of an adult on the child (19%) and wedging between two surfaces, such as the wall and a mattress (12%). All of these suffocation deaths is preventable.

Understanding infant sleep

Though their activity level while awake may make things appear different, your little one actually sleeps a great deal of the time — in fact, they spend most of their day asleep.

Understanding the difference between a baby’s sleep cycle and your own is key to identifying healthy sleep in your infant and mitigating SIDS risk.

According to, babies up to 3 months old spend between 14 and 17 hours asleep every 24 hours. By the time they are 4 to 11 months old, the average sleeping time drops to between 12 and 16 hours.

Babies naturally sleep in short bursts, rather than all at once, and though this may be frustrating for parents desperate for a few extra winks, there’s a biological reason for this.

According to pediatricians, a baby who sleeps through the night is actually in danger of SIDS, or other accidental causes of death.

Babies who sleep very soundly are less able to naturally rouse and wake if something goes wrong. If they are sleeping on their stomach, an unsafe position for young babies, there is a good chance that they can rebreathe air.

This lowers the amount of oxygen in the blood and raises the level of carbon dioxide. Unless the baby rouses and moves, it could suffocate.

As such, it’s important to recalibrate your thinking to acknowledge your child’s frequent wake-ups and instinct to rouse themselves as an indicator of good sleep health. Statistics prove that an easily roused baby is a safer baby.

Studies show that the sleep patterns of newborns are influenced by both biological and environmental factors. 3Baby sleep patterns: An evidence-based guide – Parenting Science First, the infant doesn’t have the same sleep rhythm as older children or adults.

Adults repeat a 90 to 100-minute cycle of the circadian rhythm, the internal mechanism found in the hypothalamus which controls human sleep. This rhythm moves from light to deep, to REM (Rapid Eye Movement) sleep.

Conversely, a newborn almost immediately lapses into an infant’s version of REM sleep, also called ‘active sleep.’

They arouse for short periods at different times of the night. Their sleep cycle consists of REM, transitional sleep, then quiet sleep.

Adults spend about 20% of sleep in REM, while newborns spend about half their sleeping time in the REM stage. When we are in REM, we usually don’t move much at all.

Babies, however, are quite active during this phase and retain muscle tone that helps them move quickly.

Transitional sleep

During the transitional phase of sleep, babies frequently move, vocalize, or even open their eyes. Parents often mistakenly interpret these signals as wakefulness.

By picking the baby up, changing a diaper, or trying to feed the baby, they are instead interrupting an essential sleep stage.

It’s wise to wait five minutes in order to see if your little one is actually waking up, rather than rousing them from sleep unnecessarily, as it’s best for infants not to fully wake during transitional sleep in order to preserve their sleep cycle.

Allowing your baby to sleep naturally, and wake only when ready, will prevent sleep problems in the months to come.

Good sleep training

Of course, there are strategies parents can use to help their babies become better sleepers. 4Baby sleep patterns: An evidence-based guide – Parenting Science Light cues are crucial to learning when to sleep and when to wake.

Ensure that your baby spends time in well-lit areas during the day, dimming the lights after supper, while keeping things quiet and uneventful until eventual lights-out at bedtime.

While it’s understandable for a working parent to want to convert that all-important after-dinner restful period into playtime to make up for a missed day, it’s best, for your baby’s sake, to get the sleep they need at an appropriate hour.

Allowing infants and young children to stay up past their bedtime, or develop an unnaturally late-sleeping and rising schedule, can pose serious problems when they make the transition into preschool or kindergarten.

Creating a safe sleep environment

There is a near-unanimous agreement among health professionals that the safest place for a baby to sleep is in a separate crib or bassinet in the same room as you for the first 12 months.

An easy-to-remember rule for safer sleep is Pathway’s ABC of sleep: 5ABC of sleep –

A, B, C: Alone, Back, and Crib

The baby should always sleep alone.

A baby should sleep on its back

The baby should always sleep in a crib.

And the UK guidance is similar:

A, B, C: ALWAYS sleep your baby on their BACK in a CLEAR [crib] or sleep space6The Lullaby Trust

In essence, both messages are the same. The Lullaby Trust, who partner with Public Health England to create the British guidelines, explicitly state: 7Sharing a room with your baby – The Lullaby Trust

  • You should always place a baby on their back to sleep, whether for the night or a nap
  • The safest place for your baby to sleep is in a separate [crib or bassinet] in the same room as you
  • The chance of SIDS is lower when babies sleep in a separate cot in the same room as their parents

If there seems to be a difference between the two ABCs, this has more to do with tone and tact. The British guidance emphasizes the importance of having open, non-judgemental conversations with parents about safer sleep, including co-sleeping.

Jenny Ward, Acting CEO of The Lullaby Trust says:

“Co-sleeping needs to be discussed with all families. We know from talking to parents that if they are told not to co-sleep they will then feel they cannot discuss what actually happens. As a result they will not get important advice on how to co-sleep more safely. It is a reality that even if parents do not plan to co-sleep, many still fall asleep with their babies unintentionally. Babies can and do die in high risk co-sleeping situations. If given the right advice, parents can prepare for planned and unplanned co-sleeping that will help to mitigate those risks and reduce the chance of SIDS.”

Other sleep environment factors

  • As both ABCs indicate, the very safest place for your baby is in their crib, bassinet, or moses basket in the same room as you.
  • This also means that baby should not sleep in the arms of a sleeping person, nor be placed on a couch or chair.
  • Your baby’s bed should contain nothing but the baby and a fitted sheet — though they’re cute, this means skipping the blankets, top sheets, bumper pads, quilts, and pillows, (but don’t worry, the time for their fully furnished bedroom will come!)
  • If you think your baby might become cold during sleep, use a fitted blanket garment. These are gowns, with or without feet, that zip up to the baby’s neck. Safely controlling the temperature of a room by insulating windows can also be helpful.

Safer sleep practices

In addition to the ABCs of sleep safety, there are other important rules to follow which can help protect your child. Taking these additional steps can assist your child’s healthy development and contribute to their ongoing good health.
A 2016 AAP-issued report on SIDS, and other sleep-related infant deaths, made the following recommendations to parents in addition to controlling infant sleeping environments: 8SIDS and Other Sleep-Related Infant Deaths – AAP

  • Share your room with baby: For the first year of your baby’s life, the AAP recommends that their crib be placed in the same room where you sleep. Your little one is safest when they’re sleeping in their crib near to parents.
  • Breastfeed if you can: Breast milk is considered an optimum form of nutrition for babies, and it packs the benefit of naturally generated antibodies that are passed from moms to their infants. It’s recommended that mothers breastfeed for at least six months where possible. Babies who are exclusively breastfed have a reduced likelihood of SIDS, while any amount of breastfeeding correlates with a lowered risk.9SIDS and Other Sleep-Related Infant Deaths – AAP
  • Never sleep with baby on soft furniture: Some of the most dangerous places for babies to sleep are on armchairs or couches.10[9]

Babies can suffocate if they become trapped or wedged in seat cushions. If they sleep in the arms of another sleeping person, that person’s body can crush or smother the infant, causing suffocation. It’s essential that caregivers remain awake and alert.

If you share the bed, take precautions: While official recommendations on infant sleep advise against bed-sharing, doing so is a highly personal choice, and we understand that some families also bed share. 11Co-sleeping with your baby – The Lullaby Trust

If you choose to co-sleep with your baby, make sure that pillows, sheets, and blankets, that could obstruct their airways or lead to overheating, are kept away from the baby. If breastfeeding or bottle-feeding your infant in bed, do your best to avoid falling asleep. Avoid placing babies where they could become trapped between the mattress and a wall. Finally, do not allow children and pets to be in the bed simultaneously.

Safer co-sleeping

Some families choose to bed share with their baby. If you co-sleep, whether intentionally or unplanned, there are additional risks that you must avoid:

  • Never allow an infant to share a bed with a current smoker, even if they do not smoke in bed. If a mother smoked during pregnancy, SIDS risk associated with bed-sharing rises sharply.
  • If a person is impaired because they are tired, using medications, alcohol, or illicit drugs, they must not take the baby into an adult bed.
  • Never allow bed-sharing with non-parental caregivers or other children.
  • Never share a soft-surface bed, eg., a waterbed, sofa, armchair, or old mattress.
  • Never share an adult bed if it has soft bedding like blankets, quilts, or pillows.

Try a pacifier

Pacifiers at naptime and bedtime may protect against SIDS12Moon, R. Y., Tanabe, K. O., Yang, D. C., Young, H. A., & Hauck, F. R. (2012). Pacifier use and SIDS: evidence for a consistently reduced risk. Maternal and child health journal16(3), 609-614. though the reasons why are largely unknown.

While parents may be eager to introduce a dummy to their child after hearing this good news, don’t be disheartened if they’re not immediately interested, and heed the following advice first.

  • If your baby doesn’t want a pacifier, try again a few days or weeks later. Do not use a clip or hang the pacifier round the baby’s neck.
  • If breastfeeding, make sure your routine is well established before you introduce a pacifier.
  • Thumb and finger sucking does not have the same effect, so try to discourage that habit.

Don’t smoke

Though the risks of smoking are well-documented, babies of mothers who’ve smoked during or after birth run a significantly higher risk of ill health.13[12]

Some babies who have lost their lives to SIDS were found to have a marker in their lungs indicative of exposure to cigarette smoke.

The risk of SIDS deaths in children of smoking parents also rises significantly during bed-sharing, even if parents aren’t smoking in bed.

It’s important to wash all surfaces and linens in the home. Professional smoking cessation help is available from your GP if needed.

No alcohol or illicit drug use

The use of alcohol or drugs (prescription or illicit) can potentially alter a parent’s capacity to respond to hazardous situations, be aware of their surroundings, and remain fully conscious when caring for a child.

All such faculties are required in order to mitigate SIDS risk, so it’s essential for parents to be conscious and sober for infant sleep safety.

Avoid overheating

Babies are at increased risk of SIDS if they are too hot. If you touch your baby’s hands or feet and they feel cool or cold, don’t immediately add blankets or heavy clothes.

Their standard clothes, with one additional layer, are enough to keep them cozy, with the child’s circulatory system naturally responding in cooler extremities.

If babies are sweating, they are too hot. Remove layers until they’re comfortable, and NEVER cover a baby’s face with a blanket.

Regular prenatal care

Receiving regular prenatal care during your pregnancy is an integral part of keeping your baby healthy.

After their birth, babies should see a pediatrician for regular well visits to rule out any health issues, and follow a standard schedule of immunizations that will protect both themselves and other children.

No product can detect or avoid SIDS or SUID

Although it can be tempting to invest in a home cardio-respiratory monitor intended for sleep apnea or heartbeat monitoring in order to identify or reduce SIDS risk, it’s important to know that these monitors are not correlated with the detection, or protection, of the condition.

There is no commercially available device that will monitor a baby’s vital signs.

Myths about SIDS and SUID

Unfortunately for parents, the conversation around SIDS has a history of misinformation and is often beleaguered by outdated opinions.

As with every other facet of medicine, advice changes as the facts become better known. In these cases, following the advice of your elders — no matter how well-intentioned — may be unwise.

Instead, heed the recommendations of the AAP and your pediatrician for safe infant sleep.

Here are some common misconceptions about infants and sleep safety. 14Myths and Facts About SIDS and Safe Infant Sleep – Safe to Sleep We’ll clear up the confusion and give you the latest research.

  • Babies can catch SIDS: SIDS is not a disease, but the result of certain physical and environmental conditions. While there are rare health conditions which may lead to a SUID, these are distinct genetic problems which are non-transmissible. Homes, rooms, and cribs cannot transmit SIDS or SUID risk to other children.
  • Back sleeping might allow the baby to cough: The trachea (windpipe) and esophagus (food passage) lie next to each other from the throat downward. If a person is lying on their back, their air passage is not compromised by vomit. In fact, a back sleeper has less trouble clearing obstructions.
  • Vaccinations or medications can cause SIDS: Recent research demonstrates that immunizations and medications do not raise the risk of SIDS.
  • SIDS can occur at any age: SIDS potentially occurs between birth and 12 months, after which toddlers can quickly remove themselves from most compromising situations. An exception is accidental strangulation from an unsafe crib, bedding, or other objects which should not be present in bed with the child.
  • SIDS can be prevented: No product, medication, vitamin, or regimen has the capacity to prevent SIDS. The best precaution is to create safe conditions that will lower the risk of a sudden infant death.
  • Parents who co-sleep can quickly help baby: Keeping your baby’s crib in your room for the first six months is adviseable, while moving them into your bed to co-sleep is unlikely to reduce SIDS risk.

Remember, helping to protect your new baby from sleep dangers means following a simple set of rules.

While certain circumstances will always be beyond the control of either you or your pediatrician, someday, with more study and research, safety measures might arise that will lower the risk even further.

For now, the best we can do to ensure our babies have safe sleep environments is to stay aware of the latest medical advice on infant sleep.

Your pediatrician or clinic will be happy to answer any of your questions and keep you up to date.

Please take time to review this roundup of information we’ve provided for you. Make sure you share this video with family, friends, other pregnant women, and new parents.

Bereavement: finding support

To all parents reading this who have lost a child: our hearts go out to you for your unthinkable loss. Your child’s life was precious, and your grief is all too real.

For parents who’ve experienced a loss through SIDS, the severity and trauma of the situation can be further compounded by such surrounding circumstances as a mandatory investigation.

The emotional impact of this loss will be tremendous, placing strain on relationships and affecting siblings and other family members.

Reaching out for support during this time is an important part of grieving in a healthy way. Perhaps speak with your GP for a referral into counseling, either individually, as a couple, or as a family.

Support groups also exist for families who have experienced SIDS loss, which can help you connect with others who could validate your experience and emotions.

Here are a few organizations offering help and support to those grieving child loss:

Outlook and takeaway

While SIDS is a condition that requires conscious sleep safety measures to avoid, a growing understanding of the risk factors surrounding this syndrome means that today’s parents are far more capable of avoiding it by taking basic precautions.

The AAP’s 1994 Back-to-Sleep campaign alone cut the number of SIDS deaths in the United States by half, making it abundantly clear that a baby simply being in a safe position can play a major part in avoiding SIDS fatalities.

For parents, the best course of action is to be aware of the risk factors and engage in safe sleeping/co-sleeping habits to create a healthy, happy, and low-risk sleep routine for your baby.

Neve Spicer
Written by Neve Spicer Updated on November 3rd, 2021

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