A lack of answers is partly what makes sudden infant death syndrome (SIDS) so frightening. SIDS is the leading cause of death among infants who are 1 month to 1 year old, but despite years of research and numerous studies, SIDS is still unpredictable and unpreventable. However, research into the causes of SIDS has led doctors to recommend steps parents can take to reduce the risk of SIDS in their infants. As more parents begin to follow that advice, the number of deaths from SIDS is dropping.
Searching for AnswersSIDS is frequently described as a parent's worst nightmare because it strikes without warning, usually in seemingly healthy babies. As the name implies, SIDS is the sudden and unexplained death of an infant who is younger than 1 year old. Most SIDS deaths are associated with sleep (hence the common reference to "crib death"), and infants who die of SIDS show no signs of suffering.
While most conditions or diseases usually are diagnosed by the presence of specific symptoms, SIDS is a diagnosis of exclusion, given only after all other possible causes of death have been ruled out through an autopsy, an examination of the death scene, and a complete review of the infant's medical history. These procedures help distinguish true SIDS deaths from those resulting from accidents, abuse, and previously undiagnosed conditions, such as cardiac or metabolic disorders.
When considering which babies could be most at risk, Marj Hershberger, a certified pediatric nurse practitioner, notes that no single risk factor is likely to be sufficient to cause a SIDS death. Rather, several risk factors combined may contribute to cause an at-risk infant to die of SIDS.
According to the National Institute of Child Health and Human Development (NICHD), the incidence of SIDS is greatest in infants younger than 6 months of age and increases during cold weather. African-American infants are two times more likely to die of SIDS than white infants, and Native Americans are about three times more likely than whites. More boys than girls fall victim to SIDS. Other potential risk factors include:
smoking, drinking, or drug use during pregnancy
poor prenatal care
prematurity or low birth-weight
mothers younger than 20
smoke exposure following birth
stomach sleeping
Foremost among the risk factors, however, is stomach sleeping. Numerous studies from Europe and Australia found a higher incidence of SIDS among babies placed on their stomachs to sleep than among those on their backs or sides. Some researchers have hypothesized that stomach sleeping puts pressure on the child's jaw, therefore narrowing the airway and hampering breathing.
Another theory is that stomach sleeping can increase an infant's risk of "rebreathing" his own exhaled air, particularly if the infant is sleeping on a soft mattress or with bedding, stuffed toys, or a pillow near his face. In that scenario, the soft surface could create a small enclosure around the baby's mouth and trap exhaled air. As the baby breathes exhaled air, the oxygen level in his body drops and carbon dioxide accumulates. Eventually, this lack of oxygen could contribute to SIDS.
Also, infants who succumb to SIDS may have an abnormality in the arcuate nucleus, a part of the brain that may help control breathing and awakening during sleep. If a baby is breathing stale air and not getting enough oxygen, the brain usually triggers the baby to wake up and cry. That movement changes the breathing and heart rate, making up for the lack of oxygen. But a problem with the arcuate nucleus could deprive the baby of this involuntary reaction and put him at greater risk for SIDS.
Going Back to SleepThe striking evidence that stomach sleeping might contribute to the incidence of SIDS led the American Academy of Pediatrics (AAP) to recommend in June 1992 that all healthy infants younger than 1 year of age be put to sleep on their backs (also known as the supine position). The AAP used the slogan "Back to Sleep" to remind parents of the recommended supine sleeping position. 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, distributes free literature, videos, and public service announcements urging that babies be placed on their backs to sleep.
The campaign has had dramatic success. Prior to the campaign, 70% of babies in the United States were stomach sleeping. By 1997, only 21% were sleeping on their stomachs, and the SIDS rates had dropped by 43%. Still, SIDS remains the leading cause of death in young infants, so it's important to keep reminding parents about the necessity of back sleeping.
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]."
Many parents fear that babies put to sleep on their backs would choke on spit-up or vomit. According to the AAP, however, there is no increased risk of choking for healthy infants who sleep on their backs. (For infants with chronic
gastroesophageal reflux or certain upper airway malformations, sleeping on the stomach may be the better option. The AAP urges parents to consult with their child's doctor in these cases to determine the best sleeping position for the baby.)
Some parents may also be concerned about
positional plagiocephaly, a condition in which babies develop a flat spot on the back of their heads from spending too much time lying on their backs. Since the Back to Sleep campaign, this condition has become quite common - but it is usually easily treatable by changing your baby's position frequently and allowing for more "tummy time" while they are awake.
Of course, once babies can roll over consistently - usually around 4 to 7 months - they may choose not to stay on their backs all night long. At this point, it's fine to let babies pick a sleep position on their own.
Tips for Reducing the Risk of SIDSIn addition to placing healthy infants on their backs to sleep, the AAP suggests the following measures to help reduce the risk of SIDS:
Place your baby on a firm mattress to sleep, never on a pillow, waterbed, sheepskin, or other soft surface. Do not put fluffy blankets, comforters, stuffed toys, or pillows near the baby to prevent rebreathing.
Make sure your baby does not get too warm while sleeping. Keep the room at a temperature that feels comfortable for an adult in a short-sleeve shirt. To avoid overheating, cover the baby only with a light blanket that reaches no further than the shoulders. Some researchers suggest that a baby who gets too warm could go into a deeper sleep, making it more difficult to awaken.
Do not smoke,
drink, or use drugs while pregnant and do not expose your baby to secondhand smoke. NICHD figures indicate that children of mothers who smoked during pregnancy are three times more likely to die of SIDS than those whose mothers were smoke-free; exposure to secondhand smoke doubles a baby's risk of SIDS. Researchers speculate that smoking might affect the central nervous system, starting prenatally and continuing after birth, which could place the baby at increased risk.
Receive early and regular prenatal care.
Make sure your baby has regular well-baby checkups.
Breastfeed if possible. Although there is no evidence that directly links breastfeeding with a decreased rate of SIDS, breast milk is thought to keep babies healthy.
If your baby has gastroesophageal reflux disease (GERD), be sure to follow your child's doctor's guidelines on feeding and sleep positions.
Losing a child to SIDS invariably makes a family ask questions. "An infant death leaves many unanswered questions. It causes intense grief for parents and for the whole family," Hershberger says. In searching for an explanation, however, it is important that parents do not latch on to misinformation. "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, that provide grief counseling and contacts to local support groups. Meanwhile, growing public awareness of SIDS and the steps to reduce infants' risk of sudden death hopefully will leave fewer parents searching for answers in the future
