Sudden Infant Death Syndrome

Sudden infant death syndrome (SIDS) is the sudden and unexpected death of a baby less than one year old, which remains unexplained after a thorough investigation and autopsy. SIDS is sometimes referred to as “crib death,” because many babies who die from SIDS are found in their cribs. However, cribs have not been shown to cause SIDS.

In the 1990s, national and international campaigns advising parents to put their babies to sleep on their backs have led to a decline of 50% in the rate of SIDS. Still, in the United States, SIDS remains the leading cause of death in babies who are over one month of age.

Baby boys are at higher risk for SIDS than girls.

In the USA, black and native Indian babies have a two- to threefold higher risk of developing SIDS than other babies. SIDS is more common in the winter months than in summer. Premature and low birth weight babies, and babies born to teen mothers, are at higher risk.

The incidence of SIDS is rare in the newborn period, but it rises soon after the first month. Deaths from SIDS are most common from two to four months of age. Ninety per cent of SIDS deaths occur by age six months.

Although SIDS is uncommon in newborn babies, it is a major concern in slightly older babies, and therefore it is important to take the necessary precautions right from birth.

Recommendations for preventing SIDS

The exact cause of SIDS remains unknown, but a number of risk factors have been identified, such as sleeping on the tummy, second hand smoke, overheating, premature birth, low birth weight, and young age of the mother. As a result, a number of recommendations have been suggested as a way of preventing SIDS.

Back to sleep

Numerous studies have shown that putting a baby to sleep on his tummy leads to a higher risk of SIDS. As a result, in 1992, the American Academy of Pediatrics issued a statement that babies should be put to sleep on their backs.

Infant Sleeping Position
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It is best for babies to sleep on their backs for the first 6 months of life.

The risk of SIDS when a baby is put to sleep on his side is less than that of tummy sleeping but higher than that of sleeping on his back. The problem with putting a baby to sleep on his side is that he can easily roll onto his tummy.

Some parents worry that putting their baby to sleep on his back will increase the chance of choking or spit-up. Rest assured that there is no increase in choking in babies who sleep on their backs.

Studies have shown that babies who normally sleep on their backs, but who are put to sleep on their tummy occasionally, are at an even higher risk of SIDS than babies who normally sleep on their tummies. This means that even if you consistently put your baby to sleep on his back, but your babysitter decides to put him to sleep on his tummy, he is at higher risk of SIDS. Make sure that all caregivers and babysitters are aware that they must put your baby to sleep on his back. This applies not just to night-time sleeping but also to naptime.

Avoid soft mattresses, bedding, and pillows

Soft mattresses, couches, and waterbeds are unsafe places for your baby to sleep. Soft bedding and pillows can block your baby’s nose and mouth, and therefore can interfere with his breathing and cause SIDS. Placing your baby on his tummy, face down, on soft bedding is especially hazardous. Avoid placing soft materials such as quilts, comforters, or sheepskins under your baby when he sleeps. Keep pillows, stuffed toys, and other soft objects out of his sleeping environment. Avoid bumper pads and loose bedding.

Use a firm crib mattress, covered by a tightly fitted sheet. If you use a blanket, tuck it around the crib mattress so it does not cover your baby’s face.

Do not smoke

Smoking during pregnancy puts a baby at risk for SIDS. Exposing a baby to second-hand smoke after he is born also increases the risk. Keep your baby in a smoke-free environment.

Avoid overheating

Overheating can increase the risk of SIDS. Avoid overheating your baby. Keep him lightly clothed for sleep. Make sure that his room is at a comfortable temperature for a lightly clothed adult. Your baby should not feel hot to the touch.

Keep the baby in your room

Studies show that when a parent or other committed adult caregiver sleeps in the same room as a baby, but not in the same bed, the risk of SIDS drops by 50%. Most incidents of SIDS occur in babies who sleep by themselves in a separate room, without an adult present. Putting a baby to sleep in a room with his sibling does not reduce the risk of SIDS.

Premature and low birth weight babies

Despite the “Back to Sleep” campaign, many health care providers in hospital nurseries continue to put premature and low birth weight infants to sleep on their tummy or side. This is because these babies are more easily managed in such positions, and the risk of SIDS is relatively low in the newborn period. In addition, these babies are usually on a monitor, allowing for quick detection of problems. However, parents are likely to follow their practitioner’s lead and continue placing their baby on his tummy or side when he comes home. Numerous pediatric societies recommend that all babies, including premature and low birth weight babies in hospital or at home, be put to sleep on their backs as soon as possible. If your newborn baby is in a special care nursery or neonatal intensive care unit and you are concerned that he is being put to sleep on his tummy or side, make sure to discuss this with his health care providers.

Tummy time

Babies who are placed to sleep on their backs can sometimes develop a flattening of the back of the head. This is less likely to happen if your baby spends a total of 90 minutes on his tummy every day when he is awake, and if you carry him in an upright position when he is not sleeping. Also, when you put him to sleep, try varying his head position each time.

Coping with SIDS

Victims of SIDS die without warning or medical explanation. As a result, their parents face both the unbearable sadness of losing a baby and tremendous guilt. They blame not only themselves, but also other people they may be close to. If you have a baby who has died from SIDS, try not to blame yourself or others. Understand that, although there may be ways to reduce the risks, SIDS can still happen, and there is no known cause. 

The grief of losing a baby can be overwhelming. You may experience many emotions, ranging from numbness or denial to anger or depression. You and your partner may grieve in different ways, which may cause tension in your relationship.

Hazel Pleasants, RN, MN

Andrew James, MBChB, FRACP, FRCPC