Download Print-Friendly Version (PDF)
SIDS is the diagnosis given for the sudden death of a baby under one year of age that remains unexplained after a complete investigation, including an autopsy, examination of the death scene and review of the symptoms or illnesses the baby had prior to dying and any other pertinent medical and family history. A SIDS diagnosis falls under a broader classification of infant deaths call SUID (Sudden Unexpected Infant Death). There are 4,500 SUID in the United States each year, including more than 2,200 SIDS deaths. Of these SIDS/SUID deaths, statistics indicate that as many as 80-90 percent may be the result of unsafe sleep practices.
There is mounting evidence that suggests many SIDS babies are born with brain abnormalities that make them vulnerable to sudden death during infancy. Studies of SIDS victims reveal abnormalities in the “arcuate nucleus,” a portion of the brain that controls most of the baby’s major bodily functions such as heart rate, breathing, temperature and the ability to wake from sleep. This abnormality makes babies unable to cope with challenges in their environment that a healthy baby would be able to overcome. These challenges include tummy sleeping, bed sharing, use of soft bedding, overheating and tobacco exposure.
SIDS is the leading cause of death in babies one month to one year of age. Most SIDS deaths occur when a baby is between two and four months. Ninety percent of SIDS victims die before six months. The risk of SIDS diminishes after six months. The diagnosis of SIDS is not commonly used after one year of age. However, some babies older than one year do die suddenly and unexpectedly.
Currently there is no way to predict which newborns will die from SIDS and no way to prevent it in all cases. However, there are lifesaving steps parents and caregivers can take to help protect their baby from SIDS, suffocation and accidents during sleep:
Never use wedges or positioners to prop your sleeping baby up or keep him on his back. These devices have not been tested for safety and have not been shown to be effective at keeping babies on their backs. These devices are particularly dangerous when your baby starts wiggling around during sleep.
It is important to note that bed sharing has not been found to be protective against SIDS, in fact current research indicates that bed sharing increases a baby’s risk to die by as much as 40 times. Research does, however, suggest that room sharing is protective against SIDS. Keep your baby next to where you sleep in her own separate space for at least the first six months. This provides greater safety for the baby and makes it easier to breastfeed and share closeness with your baby.
While the exact safety mechanism is not yet known, there are many possibilities for this finding. One is that the presence of a pacifier in the mouth may discourage babies from turning over onto their stomach during sleep. Because moving or turning may dislodge the pacifier, it may encourage babies to stay on their backs. Another is that the pacifier and/or sucking reflex helps keep the tongue positioned forward, keeping the airways open. Pacifier use can also help quiet a restless infant who might otherwise move more aggressively around the crib. Because pacifiers stimulate the upper airway muscles and saliva production, it is felt that pacifier use may keep babies from falling into a deep sleep, which is protective against SIDS. Regular pacifier use is protective against SIDS even if the pacifier falls out of the baby’s mouth when he or she falls asleep.
Data analyzed by scientists at the National Institute of Environmental Health Sciences suggest that breastfeeding can reduce the risk of death for infants in their first year of life. Looking at infants between 28 days and one year of age, researchers concluded that promoting breastfeeding could potentially prevent up to 720 post-neonatal deaths in the U.S. each year. Researchers compared CDC records of 1,204 children who died between 28 days and one year of causes other than congenital anomalies or cancer with those of 7,740 children still alive at one year.
This campaign is aptly named for its main recommendation to place healthy infants on their backs to sleep to reduce the risk of SIDS. The lead partners in this campaign include the National Institute of Child Health and Human Development (NICHD), American Academy of Pediatrics (AAP), First Candle/SIDS Alliance and the Association of SIDS and Infant Mortality Programs. Based on a recommendation made by the AAP in 1992, the campaign was launched in 1994 with an effort to reach every parent and caregiver in the country.
The campaign has been very successful in reaching parents and other caregivers with the Back to Sleep message. We have seen a change from 70 percent of babies placed on their stomachs to sleep in 1992 to 15 percent in 2005. Rates of SIDS have declined by more than 50 percent during that time, resulting in the most significant impact on our nation’s high rates of infant mortality in history. However, we have not reached all families and all populations. Of the more than 2,200 SIDS deaths each year, more than 70 percent were placed on their stomach to sleep. Thousands of other SUID occur as a result of bed sharing, soft bedding use and other unsafe sleep practices.
As a result, experts are recommending expanding the campaign beyond Back to Sleep to Safe Sleep to save as many lives as possible and continue have an impact on our nation’s high rates of infant mortality.
Yes, babies in the following categories are at a higher risk for SIDS:
African American babies are nearly two-and-a-half times more likely to die of SIDS/SUID than Caucasian babies, and Native American babies are nearly three times more likely to die of SIDS/SUID. The Back to Sleep campaign is being stepped up, with a special effort to get the message out to these two populations with the help of community, civic and religious groups.
At this time there is not direct link to SIDS and genetic predisposition. Metabolic disorders, which can be inherited, have at times been mistaken for SIDS. One such disorder, medium chain acylCoA dehydrogenase deficiency (MCAD), prevents the infant from properly processing fatty acids. A build up of these acid metabolites could eventually lead to a rapid and fatal disruption in breathing and heart functioning. If there is a family history of this disorder or childhood death of unknown cause (especially more than one case within a family), genetic screening of parents by a blood test can determine if they are carriers of this disorder. If one or both parents are found to be a carrier, the baby can be tested soon after birth at little cost.
This is another reason why the autopsy is so important. Tests can be done on the tissues of an infant to identify known metabolic disorders. Other research studies into possible genetic links to SIDS are ongoing.
In 1992, the AAP recommended both the side and the back sleeping position to reduce the risk of SIDS. In 1996, however, after reviewing data from various new studies, they revised their recommendation to back sleeping as the only safe sleep position for babies. These reports indicated that the risk for SIDS is greater for babies placed on their sides versus those placed on their backs, perhaps because babies placed on their sides have a higher likelihood of rolling onto their tummies. In 2005, the AAP began recommending against side sleep position for babies.
Many parents place babies on their stomachs to sleep because they think it prevents them from choking on spit-up or vomit during sleep. In fact, the opposite is true – babies are less likely to choke when sleeping on their backs. When babies sleep on their back, the esophagus (food pipe) is below the trachea (wind pipe.) As a result, the spit-up or vomit cannot be breathed into the wind pipe. When a baby sleeps on his stomach, the food pipe is above the wind pipe. Gravity would then allow for the spit-up/vomit to be breathed in, causing the baby to choke. Since babies have been sleeping on their backs, studies worldwide have not found any increase in the incidence of aspiration, choking, pneumonia or other problems.
Many parents place their baby on his or her stomach because they think the baby will be more comfortable. This may be true, but tummy sleeping is very dangerous and increases the risk of SIDS and suffocation. It appears sleep position preference is a learned behavior during the first four to six months of life. If babies are placed to sleep on their backs from birth, they will not know any other sleep position and will be comfortable sleeping that way.
Some experts feel that swaddling in the early weeks can help newborns sleep more comfortably on their backs. This can help minimize the startle reflex and ease colic symptoms in some babies. If you choose to swaddle, take time to learn how to swaddle properly before you leave the hospital. Take care not to swaddle too loosely, as the blanket can come loose and accidently suffocate your baby. Take care not to swaddle too tightly as this can compress your baby’s chest and make it difficult to breathe. Tight swaddling can also cause problems with your baby’s hips and legs. Once your baby starts to wiggle around during sleep, it is probably time to stop swaddling.
Since babies started sleeping on their backs, there has been an increase in parents reporting a flat spot on the back of their baby’s head. Experts say that this is normal and will disappear after the baby has begun to sit up and crawl. There are simple steps parents and caregivers can take to avoid flat spots: alternate the end of the crib where you place your baby’s head for sleep; alternate the arm in which you hold your baby for feedings; give your baby lots of tummy time when he or she is awake and being supervised (see below); and make sure that your baby does not spend too much time in car seats, carriers, swings and other similar products.
Yes, you should give your baby as much “tummy time” as possible when he or she is awake and being supervised. This will help strengthen your baby’s neck and upper body muscles. Begin by laying your newborn on his or her tummy, across your lap. As your baby gets stronger, place him or her on a quilt on the floor with toys within reach. This is also a great chance for the two of you to spend quality time together, on the floor playing! Tummy time can also help prevent flat spots from developing on the back of your baby’s head. Never leave your baby unattended during tummy-time. If your baby tires or is sleepy, change activities or place her in her crib, on her back, for a nap.
A recent major breakthrough in SIDS research has provided the most concrete evidence to date that SIDS is not the mystery we once thought. Ongoing research studies by Dr. Hannah Kinney at the SIDS Center of Excellence at Harvard University have identified abnormalities in the part of the brain that controls most of a baby’s major bodily functions, including heart rate, breathing, temperature and sleep/wake patterns. Babies with this defect are not able to respond to challenges in their environment. (See Triple Risk Model below)
In addition, scientists continue to explore the development and function of the brain, nervous system, heart, breathing, sleep patterns, body chemical balances, autopsy findings and environmental factors. SIDS, like other medical disorders may eventually have more than one explanation – and more than one means of prevention. More needs to be done to uncover what causes SIDS, who is at risk for the disorder and ways to lower the risk of sudden infant death. In addition to research funding provided by the NICHD, First Candle maintains its own national research program and conducts grassroots advocacy programs that help ensure Congressional allocation of adequate funding for issues related to SIDS and other sudden, unexpected infant deaths (SUID).
Recent advances in medical research shows us that babies that die of SIDS may not be as healthy as we once thought. Scientists have uncovered an abnormality in the brainstem of SIDS victims that make them vulnerable to sudden, unexpected death.
While there is still much we do not know about SIDS, a triple-risk model is often used to describe the series of events that takes place when a baby dies of SIDS:
According to this model, all three of these elements must come together for SIDS to result (some experts now feel that even two elements could trigger a sudden death.) Unfortunately, at this time, there is no way to identify which babies are at increased risk as a result of this brainstem abnormality.
Much research has been done to investigate the effectiveness of monitors in preventing SIDS. In the 1970’s and early 1980’s, it was thought that monitoring had promise in identifying infants at risk for SIDS and signaling caregivers when infants have life-threatening events that may proceed to SIDS. In September of 1986, the NICHD held a consensus conference titled, “Infantile Apnea and Home Monitoring.” After examining all available research, the consensus panel determined that monitoring is effective only in some cases to manage infantile apnea. For the normal newborn, the risks, disadvantages, and costs of monitoring outweigh the potential of identifying infants at risk for SIDS.
There are many home monitors now on the market that claim to help prevent SIDS. It is important to note that while these devices may be helpful at monitoring sound and activity in your baby’s room, they are not effective at predicting or preventing a SIDS death. These monitors can also cause great stress due to the high incidence of false alarms. The best defense against SIDS is placing your baby to sleep on his or her back, in a safety-approved crib with a firm mattress covered with only a tight-fitting crib sheet and removing all soft and fluffy bedding and other objects from the crib.
A death scene investigation is an integral part of a SIDS/SUID diagnosis to rule out accidental, environmental and unnatural causes and to provide information to researchers on risk factors. In 2004 the CDC launched an initiative to improve the investigation and reporting of SIDS/SUID, in collaboration with other federal agencies and organizations representing medical examiners, coroners, death scene investigators, emergency medical personnel, law enforcement officials, SIDS researchers, infant death review experts, and SIDS parents. As part of this effort, on March 1, 2006, CDC released the Sudden, Unexplained Infant Death Investigation (SUIDI) Reporting Form for state and local use in infant death scene investigations. The SUIDI Reporting Form replaces the Investigation Report Form that accompanied the 1996 Guidelines for the Death Scene Investigation of Sudden, Unexplained Infant Death.
Currently, approximately half of the states have mandatory autopsy legislation for the sudden death of an infant that, in many cases, includes support for the administration of compassionate bereavement services for families. Other states are in the process of establishing similar legislation. SIDS/SUID families, at the guidance of First Candle, have been at the forefront of efforts urging the funding of research, adoption of mandatory autopsy legislation, and thorough, but compassionate death scene investigations. Broader, standardized implementation of autopsy and death scene mandates is crucial to efforts to differentiate cases of SIDS from cases of child abuse, and to expand our medical knowledge about SIDS.
A SIDS/SUID death is a tragedy that prompts intense emotional reactions among surviving family members. After the initial disbelief, denial, or numbness begins to wear off, parents can fall into a prolonged depression. This depression can affect their sleeping, eating, ability to concentrate, and general energy level. Crying, weeping, incessant talking, and strong feelings of guilt or anger are all normal reactions.
Many parents experience unreasonable fears that they, or someone in their family, is in danger. Over protection of surviving children and fears for future children are common reactions. As the finality of the child’s death becomes a reality for the parents, recovery can occur. As healing begins, parents are able to begin to take a more active part in their own lives, which begin to have meaning once again. The pain of their child’s death becomes less intense but not forgotten. Birthdays, holidays, and the anniversary of the child’s death trigger periods of intense pain and suffering.
Children will also be affected by the baby’s death. They may fear that other members of the family, including themselves, will also suddenly die. Children often also feel guilty about the death of a sibling and may feel that they had something to do with the death. Children may not show their feelings in obvious ways. Although they may deny being upset and seem unconcerned, signs that they are disturbed include intensified clinging to parents, misbehaving, bedwetting, difficulties in school, and nightmares. It is important to talk to children about the death and explain to them that the baby died because of a medical problem that only occurs rarely and only in babies.
Families are encouraged to seek counseling and support. First Candle offers a bilingual, 24/7 crisis hotline and provides grief materials and resources to all those affected by the death of a baby at 1.800.221.7437 or www.firstcandle.org.
Last revised: October 2009
Last Updated: Jan 11, 2011