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SIDS is a nightmare for a parent because it strikes otherwise healthy babies without warning. SIDS is the sudden, unexplained death of infants who are less than 1 year old. Most SIDS deaths are analogous with sleep ("crib death"), and most infants who die of SIDS show no signs of distress. SIDS is the leading cause of death among infants who are between 1 month and 1 year old. Sudden Infant Death Syndrome is a mysterious killer that has left doctors and researchers with many questions. The lack of solid information is one of the reasons that it is such a frightening danger to small children. SIDS is currently considered to be unpredictable but there are some preventive measures that parents can take in order to reduce the risk of SIDS with their babies. As more parents have begun to follow these steps there has been a noticeable decrease in the number of deaths from SIDS.

While most diseases are diagnosed through specific symptoms, SIDS is diagnosed only after all other possible causes of death have been excluded. An autopsy and a complete analysis of the child's medical history are the only sure way to conclude that SIDS was the culprit. This course helps distinguish SIDS deaths from other causes such as accidents, abuse, and previously undiagnosed disorders like heart and metabolic problems.

According to Marj Hershberger, MS, RN, CPNP, of the Alfred I. duPont Hospital for Children in Wilmington, DE, no single risk factor is likely to be enough to cause a death from SIDS. Several risk factors occurring together may combine to cause an infant who's already at risk to succumb to SIDS.

According to statistics at the National Institute of Child Health and Human Development (NICHD), SIDS occurs most often between the ages of 1 and 4 months, and is highest during the fall, winter, and early spring. This is an age when babies are still too young to roll over by themselves. African American and Native American infants are two to three times more likely to die of SIDS than white infants are and boys are more vulnerable than girls are. Potential risk factors include smoking, drinking, drug use during pregnancy, poor prenatal care, prematurity, low birth-weight, mothers under 20 years old, smoke exposure following birth and stomach sleeping. Stomach sleeping is the primary risk factor in SIDS.

Statistical studies from Europe found a higher incidence of SIDS among babies sleeping on their stomachs than among those sleeping on their backs or sides. Some researchers hold that stomach sleeping puts pressure on the child's jaw, narrowing the airway and impeding their breathing.
Another theory is that sleeping on their stomach on a soft mattress or if bedding, stuffed toys, or a pillow are near his face an infant's chance of rebreathing their own exhaled air is greater. The soft surface can create a small area around the baby's mouth and trap the exhaled air. As the baby breathes his own exhaled air, the level of oxygen in his body drops and carbon dioxide builds up. This lack of oxygen may contribute to SIDS.

Infants who die of SIDS may have a problem in the arcuate nucleus. This is a part of the brain that may help control breathing and waking during sleep. If a baby is not getting enough oxygen, the brain usually stimulates the infant to wake up and cry. This is an involuntary reaction and the resulting movement changes the breathing and heart rate, making up for the lack of oxygen. A problem with the arcuate nucleus could prevent this reaction and put the baby at risk for SIDS.

The evidence on stomach sleeping influenced the American Academy of Pediatrics (AAP) to recommend in 1992 that all healthy infants under 1 year of age be put to sleep on their backs (the supine position). In 1994, that recommendation became the basis for the Back to Sleep campaign, sponsored by the NICHD in partnership with the AAP, the SIDS Alliance, and the Association of SIDS and Infant Mortality Programs. The ultimate goal of the campaign is to have fewer than 10% of American infants sleeping on their stomachs. According to Hershberger, "It's a cultural problem for us to switch our babies from stomach to back. We don't want to do it because our mothers and grandmothers have always told us we're supposed to put that baby [on his stomach]." New parents have also learned from hospitals, most of which used to place newborns on their stomachs prior to the AAP's recommendation. Hospitals and parents kept putting babies to sleep on their stomachs because they were afraid that babies put to sleep on their backs would choke on their spit or vomit. According to the AAP there is no increased risk of choking for healthy infants who sleep on their backs.

There has also been concern among parents over studies that indicate that babies who sleep on their back experience a delay in reaching early developmental milestones, such as the ability to roll themselves over. This is not a major setback. By the time they are 18 months old, children who slept on their backs as infants are developmentally the same as those who slept on their stomachs. The AAP recommends that babies spend time on their stomachs while they are awake; this encourages motor development.
The Back to Sleep program is showing positive results. The frequency of stomach sleeping declined by 66% between 1992 and 1996, according to the NICHD, and SIDS deaths were down by 38% during the same years. Prior to the AAP's recommendation of supine sleeping, between 5,000 and 6,000 babies died of SIDS every year in the United States.

The AAP also suggests the following procedures to help reduce the risk of SIDS:

Place your baby on a firm mattress to sleep. Do not put fluffy blankets, comforters, stuffed toys, or pillows in the crib with the baby. Ensure that your infant does not get too warm while sleeping. Keep the room temperature at a comfortable level for an adult in a short-sleeve shirt. Cover the baby with a one light blanket that comes up no further than the shoulders. There has been some suggestion that a baby who gets too warm will sleep too deeply, making it more difficult to wake up. Abstain from smoking, drinking, and drug use while pregnant and do not expose your baby to secondhand smoke. Figures show that children of mothers who smoked during pregnancy are three times more likely to die of SIDS; exposure to secondhand smoke doubles the baby's risk of SIDS. Researchers conclude that smoking affects the central nervous system, starting before birth and continuing after, which could place the baby at higher risk.

Make sure your baby has regular medical checkups. Breastfeed if possible. While there is no direct evidence that links breastfeeding with the rate of SIDS, breast milk is believed to enhance babies' health. If your child's doctor determines that due to some other condition you cannot place your baby on his back to sleep, put the baby on his side and extend the lower arm so the baby will not roll onto his stomach. While side sleeping is not as safe as the supine position, it is better than stomach sleeping.
"An infant death leaves many unanswered questions. It causes intense grief for parents and for the whole family," Hershberger says "Parents need to know that SIDS is not caused by vomiting and choking or other minor illnesses," she continues. "It's not caused by vaccines or other immunizations. It's not contagious. SIDS is not child abuse, and SIDS is not the cause of every unexpected infant death."

For parents who have experienced a SIDS death, there are many groups, including the Sudden Infant Death Syndrome Alliance, which provide grief counseling and local support groups. Meanwhile, public awareness of SIDS is growing and the knowledge of steps to reduce the risk of sudden death will leave fewer parents grieving in the future.


Thanks to the Nemours Foundation for their information on SIDS. The Nemours Foundation is a nonprofit organization devoted to children’s health in the United States. The Foundation operates the Alfred I. duPont Hospital for Children serving the Philadelphia/Wilmington area, and the Nemours Children’s Clinics throughout Florida.