Sudden Infant Death Syndrome

Sudden Infant Death Syndrome (also known as SIDS) refers to the sudden death of an apparently healthy infant under 1 year of age whose death cannot be explained even after a complete investigation.


for searching the Internet and other reference sources



Prenatal Care

Taking Care

Mrs. Wyatt is doing all the things her doctor told her to do with her new baby. She puts him to sleep for naps and at night on his back instead of on his stomach. She makes sure the crib has a mattress that is firm, and that there are no blankets, pillows, or toys around the baby. She refrains from bundling her baby in thick clothing before putting the baby to bed.

The doctor recommended these things because they reduce the risk of Sudden Infant Death Syndrome (SIDS), a mysterious disorder that is a leading cause of death for children between the age of 1 month and 1 year.

SIDS kills more than 3,000 babies a year in America, usually while they are asleep in cribs. But since mothers like Mrs. Wyatt started to put their babies to sleep on their backs, and to adopt other preventive strategies, the number of SIDS deaths has dropped more than 40 percent.

No one knows for sure why these babies die. Most of the babies appear to be healthy until their deaths.

Parents often feel guilt mixed with their grief over the death. They think perhaps there was something they could have done. But SIDS is no one's fault.

* vaccination (vak-si-NAY-shun) is taking into the body a killed or weakened germ, or a protein made from such a microbe, in order to prevent lessen, or treat a disease.

What Is SIDS?

Researchers have not discovered a cause for Sudden Infant Death Syndrome in the more than 30 years they have been studying it. In fact, it is easier to say what SIDS is not than what it is. SIDS does not result from suffocation, choking, vomiting, or a fatal reaction to a vaccination * . A baby does not catch it like a cold.

The only time doctors say that a baby has died of SIDS is if no other cause of death is found after there has been an autopsy * , an investigation of the place where the baby died, and a review of the baby's medical history.

Recent research suggests that infants who die of SIDS might have a problem in an area of the brain that controls two functions while they are asleep: breathing and waking up. This problem area in the brain, however, might not be enough on its own to cause SIDS. Other things may have to happen to reduce the amount of oxygen a baby gets, or to disrupt the baby's breathing and heart rate.

For example, babies might not get enough oxygen when they breathe air that is trapped in soft beds or in folds of blankets near their mouths. This is not the same as suffocation, which usually involves completely blocking a person's ability to take in air. In SIDS, the babies may be getting air but not enough oxygen, because they are breathing in their own exhaled breath.

Respiratory infections such as a cold or other ailment also can make breathing difficult for a baby.

Usually, babies would wake up and cry if they were not breathing well. But it may be that some babies cannot process the signals in the brain when they are not breathing properly.

These examples could help explain why babies who sleep on their stomachs or have infections are at higher risk of SIDS. It also might explain why SIDS is more likely to occur in the winter, when the risk of infection is higher and babies might be sleeping with more bedclothes or blankets.

Researchers are investigating other possible physical problems that could contribute to the risk of SIDS. One possible factor is an immune system * disorder that creates too many white blood cells and proteins, which disrupt the brain's control over breathing and heart rate.

Like many disorders, SIDS might have a combination of factors that cause it, including some that have not been discovered.

Who Is at Risk for SIDS?

Although research is beginning to suggest causes for SIDS, there is still no way to predict who will die of the disorder. The vast majority of babies who are laid to sleep on their stomachs, have infections, or sleep with blankets do not die from SIDS. Others who sleep on their backs in ideal conditions still die of the disorder.

There are no warning signs of SIDS before a baby dies. Doctors only diagnose it after ruling out other possible causes of death.

Certain things are known. SIDS can happen any time within the first year, but it occurs most often between the first and fourth month after birth. Seldom does it occur within the first 2 weeks following birth or after 6 months.

* autopsy (AW-top-see) is the examination of a body after a person has died, to determine the cause of death.

* immune system is the system that protects the body from diseases. It includes elements such as the thymus, spleen, lymph nodes, bone marrow, and antibodies (AN-te-bod-eez),

The Back to Sleep Campaign

For decades, parents thought it was best to put babies to sleep on their stomachs. They thought that if babies were on their backs, they would choke on their vomit if they threw up.

Doctors today say that should not be a concern. In fact, a national Back to Sleep Campaign was launched in 1994 by the U.S. National Institute of Child Health and Human Development (NICHD) and other organizations to inform parents that they should put healthy babies to sleep on their backs, because doing this appears to reduce the risk of SIDS.

It was in 1992 that the American Academy of Pediatrics first recommended that babies sleep on their backs. Between 1992 and 1997, the number of children sleeping on their stomachs dropped from 70 percent to 21 percent, and the death rate from SIDS dropped by 42 percent.

The Back to Sleep campaign also informed health professionals and the general public about other ways to lower the risk of SIDS. These include:

  • Having the mother avoid smoking during pregnancy
  • Making sure the mother gets medical care during pregnancy
  • Having family members avoid smoking around the baby after it is born
  • Making sure the baby gets ongoing medical care after it is born
  • Having the mother breast-feed the baby
  • Providing the baby with a firm mattress
  • Keeping pillows, blankets, and toys in the crib from crowding the baby
  • Not dressing a baby in too many clothes when the baby is sleeping.

Not all babies should sleep on their backs. A few have problems with their airways or keeping food down. Doctors may recommend in these rare cases that the babies be placed on their stomachs on a firm mattress without soft pillows, blankets, or plush toys.

Some parents have misunderstood the intentofthe Backto Sleep Campaign. They never put their children on their stomachs, even when they are awake. Doctors say it is important for children's physical and mental development to spend sometime on their stomachs while they are awake, so long as an adult is watching.

What Are the Risk Factors for SIDS?

A baby is more likely to die of SIDS if the baby has:

  • A mother who smoked during pregnancy
  • A mother less than 20 years old
  • A mother who did not receive proper medical care before her baby was born
  • A birth before the full 9 months of a normal pregnancy
  • A lower than normal birth weight
  • Family members who smoked around the baby.

However, babies who are breast-fed have a lower risk of SIDS than babies who are fed with a bottle. One possible reason might be because breast-feeding helps reduce the risk of the types of infections that may contribute to breathing problems.



Horchler, Joani Nelson, and Robin Rice Morris. The SIDS Survival Guide: Information and Comfort for Grieving Family and Friends and Professionals Who Seek to Help Them. Revised and updated edition. Hyattsville, MD: SIDS Educational Services, 1997.

Guntheroth, Warren G. Crib Death: The Sudden Infant Death Syndrome. Third edition. Armonk, NY: Futura Publishing Company, Inc., 1993.


The National Institute of Child Health and Human Development (NICHD), part of the U.S. National Institutes of Health (NIH), posts information about SIDS on its website, which also includes information on the Back to Sleep Campaign.
Telephone 800-505-2742

Sudden Infant Death Syndrome Network, P.O. Box 520, Ledyard, CT 06339. This organization is dedicated to providing information on SIDS, and support for families who lose a baby. It features information in more than a dozen languages.

National SIDS Resource Center, 2070 Chain Bridge Road, Suite 450, Vienna, VA 22182.
Telephone 703-821-8955

SIDS Alliance, 1314 Bedford Avenue, Suite 210, Baltimore, MD 21208. SIDS Alliance is a national network of SIDS support groups.
Telephone 800-221-7437 or 410-653-8226

See also
Tobacco-Related Diseases

Also read article about Sudden Infant Death Syndrome from Wikipedia

User Contributions:

Comment about this article, ask questions, or add new information about this topic: