What Is SIDS?

The major cause of death in infants from 1 month to 1 year of age, with most deaths occurring between 2 and 4 months.

• sudden and silent-the infant was seemingly healthy
• a death often associated with sleep and with no signs of suffering
• a recognized medical disorder
• determined only after an autopsy, an examination of the death scene, and a review of the infant's and family's clinical histories
• a diagnosis of exclusion
• an infant death that leaves unanswered questions, causing intense grief for parents and families

What SIDS is not

• preventable, but the risk can be reduced by placing the baby on his or her back to sleep on a firm surface, by making sure the baby has a smoke-free environment, and by keeping the baby from being overheated
• suffocation
• caused by vomiting and choking or by minor illnesses such as colds or infection
• caused by the diphtheria, pertussis, tetanus (DPT) vaccines or other immunizations
• contagious
• child abuse or neglect
• the cause of every unexpected infant death

What Are the Most Common Characteristics of SIDS?

A SIDS death occurs quickly and usually during sleep. SIDS is rare during the first month of life. Although SIDS can occur in older infants, most SIDS deaths occur by the end of the sixth month, with the greatest number occurring in infants between 2 and 4 months of age.

In the United States , more SIDS cases are reported in the fall and winter than in spring or summer. SIDS occurs more often in boys than in girls (approximately a 60- to 40-percent male-to-female ratio). African-American and American-Indian infants are two to three times more likely to die from SIDS as other infants. Several government agencies are intensifying efforts to reach these populations with the latest information about SIDS.

How Many Babies Die from SIDS?

Each year between 1983 and 1992, the average number of reported SIDS deaths ranged from 5,000 to 6,000. Over the past few years, especially since the mid 1990s, the number of SIDS deaths has declined significantly. The National Center for Health Statistics (NCHS) reported that in 2002 in the United States, 2,295 infants under 1 year of age died from SIDS, still when considering the number of live births each year, SIDS remains the leading cause of death in the United States among infants between 1 month and 1 year of age and the third leading cause of death overall among infants less than 1 year of age.

Although the overall SIDS rates have declined in all populations throughout the United States , disparities in SIDS rates and prevalence of risk factors remain in certain groups. SIDS rates are highest among African Americans and American Indians and are lowest among Asians and Hispanics.

* Per 100,000 live births by group.
Source: National Center for Health Statistics (NCHS).

SIDS Deaths Require Special Understanding

Any sudden, unexpected death disturbs the sense of normalcy and security for the victim's family. Simply put, babies are not supposed to die. Because the death of an infant is a disruption of the natural order, it is especially traumatic for parents, other family members, and friends. Like any sudden death, a SIDS death leaves a family with a sense of shock and loss and an urgent need to understand what happened. Lack of a discernible cause, the suddenness of the death, and possible involvement of law enforcement authorities make a SIDS death even more difficult.

A SIDS death is as tragic as a death from any readily definable disease or cause. Thus, investigators compiling or reviewing the case histories should be especially sensitive and recognize that the family may view this process as an intrusion, even a violation, of their grief. The interviewer should also be sensitive to the family's cultural practices and traditions. The interviewer should point out to the family that although obtaining the case histories may be stressful, this information may reveal that the death could not have been prevented, which may provide some solace to a grieving family.

Are There Ways to Reduce the Risk of SIDS?

Currently there is no known way to prevent SIDS, but there are things that parents and caregivers can do to reduce the risk of a SIDS death. For example, researchers now know that the mother's health and behavior during her pregnancy and the baby's health before birth seem to influence the occurrence of SIDS.

Scientists also know that certain environmental and behavioral influences (called risk factors) can make an individual more susceptible to disease or ill health. Although risk factors are not necessarily the cause of a condition, by studying risk factors, scientists are able to better understand a disease or condition, which often leads to detecting a cause.

SIDS researchers and clinicians continue to try to identify risk factors that can be modified or controlled to reduce an infant's risk for SIDS. Various factors can increase the risk for SIDS:

Infant Sleep Position
In April 1992, the American Academy of Pediatrics (AAP) Task Force on Infant Sleep Position issued a statement recommending that infants be placed on their backs to sleep to reduce the risk of SIDS. Then, in 1994, the U.S. Public Health Service, AAP, the SIDS Alliance, and the Association of SIDS and Infant Mortality Programs cosponsored the Back to Sleep campaign, a national public service initiative to disseminate AAP's recommendation that infants be placed on their back to sleep.

Between 1992 and 1998, among U.S. infants, stomach (prone) sleeping decreased from more than 70 percent to approximately 20 percent. During that same time frame, the number of SIDS deaths declined by more than 40 percent .Not surprisingly, most researchers, policymakers, and SIDS professionals agree that this significant decline occurred largely as a result of changing sleep position.

Rates of SIDS are over twice as high among American Indians and African Americans compared with Whites. Prone sleeping was found to be a significant risk factor for SIDS in an African- American urban sample .These authors recommend educational outreach to the African-American community.

Another recent study of the relationship between infant sleep position and SIDS concluded that infants placed in an unaccustomed prone or side sleeping position are at a higher risk of SIDS. This ethnically diverse, population-based, case-controlled study was conducted in 11 counties in California . The health message from this research is that babies should be on their backs for all sleep, including naps.

Exposure to Smoke
Researchers have concluded that if a mother smokes during or after pregnancy, she is placing her infant at a greater risk for SIDS (AAP, 2000). Some studies suggest that exposure of the newborn to tobacco smoke (whether or not the mother smokes) may be associated with increased risk for SIDS. In a 1997 policy statement, AAP cautioned, "Exposure of children to environmental tobacco smoke is associated with increased rates of lower respiratory illness and increased rates of middle ear effusion, asthma, and SIDS".

Overheating
According to AAP (2000), some evidence points to an association of the amount of clothing or blankets on an infant, room temperature, and the time of the year with an increased risk for SIDS. The increased risk associated with overheating is particularly clear when infants are placed on their stomachs (prone).

AAP cautions that the possible relationship between clothing and climate as stand-alone factors (or as a cluster of environmental risk factors) is less clear. Moreover, although the number of recorded SIDS deaths has been higher in the winter months, that increase may be due to the greater frequency of colds, flu, and other infections during the winter.

Infant Bedding
Researchers and consumer safety advocates continue to look for a possible link between SIDS and soft bedding. During 2000, seven major retailers joined with the U.S. Consumer Product Safety Commission (CPSC) to kick off a nationwide campaign promoting safe bedding practices for infants. Many retailers are developing public service campaigns to spread this message to parents and other infant caregivers. The hope is that by circulating this information, infant deaths will be reduced and that those responsible for infant care will receive one consistent message about ensuring a safe sleeping environment for babies.

In recent safety alerts, CPSC has warned parents to guard against unfounded claims from manufacturers of some infant bedding materials that the use of certain products can reduce SIDS. Parents and other caregivers need to be aware that there is no product currently available that can guarantee prevention of a SIDS death.

Other Risk Factors

Maternal Risk Factors:
are associated with how the mother's behavior and health affect the infant before and after birth.

Maternal risk factors include:

• age less than 20 at first pregnancy
• a short interval between pregnancies
• late or no prenatal care
• smoking during and/or after pregnancy
• placental abnormalities
• low weight gain during pregnancy
• anemia
• alcohol and substance abuse
• History of sexually transmitted disease or urinary tract infection.

How to Lower Your Baby's Risk of SIDS: Back Sleeping and Safe Bedding *

• make sure that everyone who cares for your baby puts the baby on his or her back to sleep
• use a firm, tight-fitting mattress in a crib that meets current safety standards
• remove pillows, quilts, comforters, sheepskins, stuffed toys, and other soft products from the crib
• dress your baby in sleep clothing so that you will not have to use any other covering over the baby
• place your baby so that his or her feet are at the bottom of the crib
• tuck a thin blanket around the bottom of the crib mattress, reaching only as far as the baby's chest
• make sure the baby's head remains uncovered during sleep
• keep your baby warm, but not too warm
• make sure that everyone who cares for your baby understands the dangers of soft bedding
• avoid adult beds, waterbeds, sofas, or other soft surfaces for sleep

(By the National/Sids Infant Death Resource Center)