What Causes SIDS and How Can it be Prevented?

By Alison Heyerdahl

As a new parent, the mention of SIDS can send shivers down your spine and get you up all night checking on your (finally!) sleeping baby.  But you can rest assured, knowing that the incidence of SIDS is very low.  In fact, only 0,0009% of babies succumb to SIDS, and there is a lot you can do to prevent it. 

What is SIDS?

SIDS stands for Sudden Infant Death Syndrome and is defined as the sudden and unexpected death of an apparently healthy infant.  Most SIDS cases occur during sleep and are 12.9 times more likely in babies that sleep on their stomachs.  Some babies are more at risk than others.  For example, it is more common in boys than in girls and usually affects younger babies – those between one and four months old.   Other at-risk groups include premature babies, low birthweight babies, and infants exposed to cigarette smoke.

What is the leading cause of SIDS?

Although researchers are still unsure about the causes of SIDS, experts believe that babies who fall victim to the syndrome have an immature arousal center in the brain.  In other words, they can’t wake themselves up when they’re having trouble breathing. Researchers have proposed the “Triple Risk Model” as an explanation for how SIDS occurs.  According to this model, three conditions exist at the same time:

• The baby has an underlying brainstem abnormality preventing him from responding to high carbon dioxide or low oxygen levels in the blood.

• The baby is placed face down on his stomach.

• The baby is under six months old – in which case they don't have the motor control to move out of the face-down position.

 Factors that may place a baby at a higher risk of succumbing to SIDS include the following:

• Babies that sleep on their stomachs or sides, rather than on their backs.

• A soft sleeping surface with too many toys or soft blankets.

• Exposure to passive smoke in the household.

• Mothers who smoke during pregnancy (three times more likely to have a baby die from SIDS).

• Babies who are born to very young mothers (under the age of 20 years old).

• Babies born to mothers who had little prenatal care.

• Those who had a sibling die of SIDS.

How is SIDS diagnosed?

SIDS is determined as the cause of a baby's death when all other reasons have been ruled out.  Investigations such as an autopsy and a detailed history of events are usually conducted, and if nothing else can be found, SIDS is determined as the cause of death. 

How can SIDS be prevented?

Although great strides have been made in determining the possible causes of SIDS, researchers are still not 100% certain why it occurs.  As a result, there is no guarantee that SIDS can be prevented.  However, there are precautions you can take to reduce the chances of it occurring:

• Put your baby to sleep on her back.  According to the 'Triple Risk Model' mentioned previously, babies who sleep on their stomachs are at a greater risk of succumbing to SIDS because they don't have the motor control in their necks to move their heads.  Babies should not be placed on their sides either, as it doubles the risk of SIDS.  Dr. Moon, a member of the American Academy of Pediatrics (AAP) Task Force on SIDS, says, "It's easier for an infant to roll onto her tummy from her side than from her back." 

• Do not put anything in the crib with your sleeping baby.  Babies should sleep in a crib with a tightly fitted sheet on a mattress that reaches right to the edges of the crib.  Toys, blankets, pillows, or an improperly fitted mattress can cause suffocation.  Swaddle your baby in a receiving blanket or use a sleep sack if you are worried about her getting cold at night, but ensure that your baby doesn’t get too warm.

• Maintain a comfortable temperature in her room.  A baby that overheats is also at a greater risk of succumbing to SIDS.  The theory is that a baby who gets too warm may be difficult to rouse if she experiences trouble breathing.  It is best to set the thermostat to 68 degrees and dress your baby in light layers that you can remove if she gets too hot. 

• Make sure your baby has room to move unrestricted around her crib.  Babies that are put to sleep in very restrictive spaces can get into dangerous positions while sleeping.  Avoid narrow cribs or small beds.  Your baby should be able to move around a bit and squirm while sleeping.

• Be cautious with co-sleeping.  New parents are often exhausted from having to wake up all night to feed their infants.  As a result, it is easy for babies to be suffocated by you or your spouse rolling on top of her.  Pillows and blankets in the bed also pose a risk to newborn babies.  If you decide to co-sleep with your baby, move the crib into your bedroom, and place her back in her own bed after feeding.

• Give your baby a pacifier.  As counterintuitive as it seems, the American Academy of Pediatrics suggests that parents give their babies pacifiers at night and for naps during the first year.  Although researchers do not know for sure why it helps, pacifiers significantly decrease the incidence of SIDS.  They suspect it may be because sucking on a pacifier moves the baby's tongue forwards, which opens up the airways, and that babies who suck on pacifiers don't fall into as deep a sleep. 

• Don’t smoke around your baby.  It has been found that babies who inhale passive smoke are more prone to succumbing to SIDS.  The occurrence of SIDS doubled when both parents smoked.  Quitting smoking is one of the best things you can do for your baby’s health — and your own.

Conclusion

SIDS is the sudden unexplained death of a baby younger than one-year-old.   Around 2300 babies in the United States succumb to SIDS each year, and some are more at risk than others.  Although there is no guarantee, there are measures you can take to prevent its occurrence.  Ensuring that you place your baby on her back for sleeping, removing pillows, blankets, and toys from her crib, not smoking around your baby, and giving her a pacifier for sleeping can drastically reduce the chances of SIDS.