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About SIDS - Detailed Description of SIDS

What's the truth about this threat to the lives of babies?
When and how Sudden Infant Death Syndrome (SIDS) strikes is mostly still a mystery to doctors and parents alike. But take this opportunity to educate yourself on what is currently known about this disease.
  • SIDS is the most common cause of death in infants from 1 month to 1 year of age, with most deaths occurring between 2 and 4 months.
  • SIDS is Sudden and Silent, the infant was seemingly healthy; unpredictable and unpreventable.
  • SIDS is a death that occurs quickly, often associated with sleep and with no signs of suffering.
  • SIDS is determined only after an autopsy, an examination of the death scene, and a review of the clinical history.
  • SIDS is designated as a diagnosis of exclusion.
  • SIDS is a recognized medical disorder listed in the International Classification of Diseases, 9th Revision (ICD-9).

SIDS - An infant death that leaves unanswered questions, causing intense grief for parents and families.

There are many misconceptions about SIDS, resulting from misinformation and fear. Read on as we debunk some of these myths:

  • SIDS is not caused by vomiting and choking or minor illnesses such as colds or infections.
  • SIDS is not caused by the diphtheria, pertussis, tetanus (DPT) vaccines or other immunizations.
  • SIDS is not contagious.
  • SIDS is not caused by child abuse.
  • SIDS is not the cause of every unexpected infant death.

SIDS Facts - What you need to know about sudden infant death syndrome.

Here's what every parent should know about sudden infant death syndrome (SIDS).

What is SIDS?
Sudden infant death syndrome (SIDS) is the sudden death of an infant under 1 year of age, which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history.

What are the possible causes?
No one knows for sure, but plausible theories include respiratory obstruction, genetic vulnerability, brain-stem birth defects, and infection. Recent studies have begun to link it to a shock-producing by-product of E. coli.

What are the most common characteristics of SIDS?
Most researchers now believe that babies who die of SIDS are born with one or more conditions that make them especially vulnerable to stresses that occur in the normal life of an infant, including both internal and external influences. SIDS occurs in all types of families and is largely indifferent to race or socioeconomic level. SIDS is unexpected, usually occurring in otherwise apparently healthy infants from 1 month to 1 year of age.

When is a death from SIDS most likely to occur?
Most deaths from SIDS occur by the end of the sixth month of a child's life, with the greatest number taking place between 2 and 4 months of age. A SIDS death occurs quickly and is often associated with sleep, with no signs of suffering. More deaths are reported in the fall and winter (in both the northern and southern hemispheres) and there is a 60- to 40-percent male-to-female ratio.

Is SIDS the leading cause of death among infants under the age of 1 in the U.S.?
Yes. When considering the overall 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 third only to congenital anomalies and short gestation/low birth weight as the leading overall cause of death for all infants around the world less than 1 year of age.

How many babies die from SIDS?
For about 10 years, from 1983 through 1992, the average number of SIDS deaths reported annually ranged from 5,000 to 6,000. Beginning in 1992, this number began to change. In the past few years, especially in the mid 1990s, the number of SIDS deaths declined significantly resulting from increased public education programs, such as the Back to Sleep campaign. The National Center for Health Statistics (NCHS) reported that, in 1997, in the United States, 2,991 infants under 1 year of age died from SIDS, down from 3,050 in 1996. Preliminary figures show that, in 1998, 2,529 infants died from SIDS.

How do medical professionals diagnose SIDS?
Often the cause of an infant death can be determined only through a process of collecting information, conducting sometimes complex forensic tests and procedures, and talking with parents and physicians. When a death is sudden and unexplained, investigators, including medical examiners and coroners, use the special expertise of forensic medicine (application of medical knowledge to legal issues). SIDS is no exception.

What are the risk factors for SIDS?
Risk factors are those environmental and behavioral influences that can provoke ill health. Any risk factor may be a clue to finding the cause of a disease, but risk factors in and of themselves are not causes. 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, but these variables are not reliable in predicting how, when, why, or if SIDS will occur. Maternal risk factors include:

  • Cigarette smoking during pregnancy
  • Maternal age less than 20 years
  • Poor prenatal care
  • Low weight gain
  • Anemia
  • Use of illegal drugs
  • History of sexually transmitted disease or urinary tract infection

These factors, which often may be subtle and undetected, suggest that SIDS is somehow associated with a harmful prenatal environment. Health professionals make use of three avenues of investigation in determining a SIDS death:

  • Autopsy
  • Death scene investigation
  • Review of victim and family case history

Unique Grief
When a baby dies, it is beyond devastating. Hopes and dreams are shattered. Everything that should be -- a joyous home, a new life, a vibrant child -- is replaced by the most profound grief. There's no set time for how long it takes to feel solace following the death of a bay, says Penelope Bushman Gemma, a psychiatric nurse clinician at Columbia University School of Nursing, who works with families who have experienced the death of a child. Some parents cry; others feel confused. Parents may experience anger, confusion, disbelief, a sense of failure, and sleeplessness, all of which are normal, explains Michael R. Berman, MD, clinical professor of obstetrics and gynecology at Yale University School of Medicine. You can have such contrasting feelings, and all at the same time. It's also common for parents to go through post-traumatic stress symptoms, such as nightmares. But perhaps most heartbreaking is the feeling of responsibility for the baby's death, regardless of what caused it. Parents who lose a child to SIDS, for instance, are often still questioning every decision they made.

Start the Healing Process
Even though the grieving process is unique in every family, there are things you can do to make life easier for all of you in the wake of tragedy. For couples whose children die of seemingly random causes, understanding the cause of death can help to bring some sense of peace. Your hospital can provide an autopsy that may reveal what went wrong. If parents can't bear the thought of looking at that information so soon after the child's death, they still have the right to look at the baby's medical records, even long after the loss, says Gemma.

Another source of comfort may be speaking with a professional, such as a bereavement counselor or member of the clergy. Friends and family can also provide support, whether in the form of a shoulder to cry on or preparing meals.

While leaning on loved ones for support helps, some parents find that what helps them most is talking to others who have had the same experience. As time goes by, though, the type of support that families need may change. Sometimes being around other families suffering through the same thing can feel like opening old wounds. At that point, you might want to switch to a private counselor. It's also important to remember that what you don't do is key to the healing process as well. Certain situations -- a child's birthday party, a baby shower -- may be too painful to bear. According to experts, this type of self-preservation is very helpful. Even if it's a close friend's or relative's gathering, you have the right to choose what you can and can't handle, says Gemma. It's fine to say "I love your kids, but right now it's too hard for me to be there."

Handling Home, Friends, and Family
Your child's nursery, along with her toys and clothes, need to be dealt with. And you'll need to break the news to friends and relatives. How do you handle these tasks? There's no right way, but experts suggest taking the least painful path and asking for help. If going over your child's story again and again is too hard, for example, send a mass e-mail. When it comes to the child's nursery, some parents choose to simply close the door until they're prepared to face it. For others, donating things to charity is a way to do something good in the wake of a tragedy. If you can't bear to pack the items yourself, ask a friend or family member to do it for you.

Honoring the Baby
Feeling better does not have to mean forgetting your child. There are many ways to honor the spirit of your baby. Life-affirming family rituals can also bring back a sense of hope. The March of Dimes ( offers a bereavement kit for families who have lost a baby. The packet includes a memory envelope, in which parents can preserve personal items, such as a photograph. It also provides information about the emotional issues surrounding loss, advice for friends and family, an insert for parents thinking about another pregnancy, a resource directory, and fact sheets on the medical reasons behind some infant deaths.

But you needn't do anything large to make an important statement about your child. For many, a contribution to a favorite charity is a soothing way to do something positive in your baby's name. Though most parents feel like they'll never get over what happened, as the healing progresses, the intensity of grief eventually subsides. Parents who've lost a child will always have a part of that baby living inside their hearts and minds, but eventually they will reach a point in their lives where they can actually laugh again.

The basics for protecting your baby.

WHAT: Sudden infant death syndrome, also called crib death, is the unexplained death of a healthy infant. It's the leading cause of fatality in babies 1 month to 1 year old, affecting 2,500 a year.
WHO: Boys are slightly more likely to die of SIDS.
WHEN: Most deaths occur between 2 and 4 months of age.
HOW: 48 percent of deaths are attributable to baby's sleeping on his front or side, according to a recent study; 16 percent of cases were linked to co-sleeping (if the mother smoked or drank).
WHY: No one really knows. But studies show that putting your baby to sleep on his stomach raises the probability that he'll rebreathe his own expired gas, causing suffocation. Overheating is also a possible factor.
PREVENTION: Always put baby to sleep on his back. Never put him to bed on a sofa or waterbed. Keep pillows, comforters, and stuffed animals out of the crib. Never smoke or drink when co-sleeping. Don't overdress baby for bed, and make sure his head remains uncovered.

Sources: National Sudden Infant Death Syndrome Resource Center
Sources: National Sudden Infant Death Syndrome Resource Center; The Associated Press

Any sudden, unexpected death threatens our sense of safety and security. We are forced to confront our own mortality. This is particularly true in a sudden infant death. Quite simply, babies are not supposed to die. Because the death of an infant is a disruption of the natural order, it is traumatic for parents, family, and friends. The lack of a discernible cause, the suddenness of the tragedy, and the involvement of the legal system make a SIDS death especially difficult, leaving a great sense of loss and a need for understanding.

The information on this Web site is designed for educational purposes only. It is not intended to be a substitute for informed medical advice or care. You should not use this information to diagnose or treat any health problems or illnesses without consulting your pediatrician or family doctor. Please consult a doctor with any questions or concerns you might have regarding your or your child's condition.