Sudden Infant Death Syndrome

Sudden Infant Death Syndrome (SIDS) is the sudden, unexpected death of an apparently healthy infant remaining unexplained after an autopsy, death scene investigation, and a medical history review. SIDS continues to be the leading cause of infant death, claiming the lives of approximately 3000 infants in the United States each year. Although the cause(s) of SIDS has continued to be undetermined, factors that can decrease the risk of SIDS are being identified. As the body of research expands, it seems most likely that SIDS will have more than one explanation.

What is Sudden Unexpected Death of an Infant? (SUDI)

Sudden Unexpected Death of an Infant is any infant death that is unexpected and initially unexplained. Frequently, a cause of death is determined after a thorough investigation and autopsy by a medical examiner and coroner. The deaths that remain unexplained are listed as SIDS. Therefore, SIDS is a type of Sudden Unexpected Infant Death.

What is Sudden Infant Death Syndrome? (SIDS)

Sudden Infant Death Syndrome (SIDS) is the sudden death of an infant under one year of age, which remains unexplained after a thorough investigation including a complete autopsy, examination of the death scene and review of the clinical history.

In the United States, SIDS is the major cause of death in infants from 1 month to 1 year. Most deaths occur between 2-4 months of age. Typically, a seemingly healthy infant dies suddenly and unexpectedly, usually during a period of sleep. A diagnosis is made after all the possible causes of death have been excluded. SIDS can occur in families of any race, socio-economic status, religion or nationality.

Causes of SIDS remain unexplained. However, SIDS is not caused by suffocation, child abuse, immunizations, vomiting, choking or by minor illnesses such as a cold or infection. SIDS is not contagious.

Is SIDS Preventable

It is important to follow the risk reduction steps below. However, because risk factors are not, in and of themselves, causes of SIDS, it is not always possible to prevent unexplained infant death (SIDS).

What practices may contribute to Sudden Unexpected Death of an Infant?
  • Placing the infant on tummy or side when sleeping.
  • Placing the baby on loose bedding or soft sleep surfaces such as, quilts, comforters, sheepskin, pillow-like toys, pillows; or sleeping on a waterbed, couch or chair. These keep the baby from breathing easily.
  • Infant exposure to any tobacco smoke during and after pregnancy.
  • Bed sharing with other children or adults.
  • Overdressing/bundling the baby too tightly in heavy blankets or a room that is too hot.
  • Preterm and low birth weight infants.
  • Maternal risk factors such as:
  • age less than 20 at first pregnancy
  • a short interval between pregnancy
  • late or no prenatal care
  • placental abnormalities
  • low weight gain during pregnancy
  • alcohol and substance abuse
  • smoking
  • history of sexually transmitted disease or urinary tract infection


What can be done to reduce the risk of unexpected infant deaths?

The most important step to prevent unexpected death is to provide a safe sleeping environment for all infants. Every year, some infants die while sleeping. Parents can reduce the risks of this tragedy by knowing and following these simple guidelines that will help meet the goal of making sure the sleeping baby's breathing remains clear and unobstructed, and that the baby does not get into a position that could cause injury.

These steps should be reviewed with anyone else who cares for the baby. (i.e., relatives, grandparents, childcare providers, babysitters)

  • Place babies on their back to sleep. Side sleeping is not advised. Do not use any pillows, cushions or blankets to prop the baby.
  • Use a firm mattress, closely fitted to the sides and bottom of the crib. Use a crib that meets the current safety standards (2 3/8 inch openings). Keep the crib free of soft objects such as pillows, comforters, soft bedding or stuffed animals.
  • Do not bundle the baby too tightly in heavy blankets or clothing. The bedroom temperature should be kept comfortable for a lightly clothed adult.
  • Keep the head and face uncovered. Consider using a one-piece sleeper/suite. If a blanket is used, it should only reach as far as the baby's chest.
  • Maintain a smoke free environment. Never smoke around a baby.
  • A sleep environment separate from, but close to the parents is recommended. It is suggested that parents place a crib, bassinet or cradle that meets safety standards near the bed, instead of having the baby sleep in bed with the parents. Do not put the baby to sleep on an adult bed or sofa. Sometimes a baby is injured by rolling off an adult bed or sofa.
  • Breastfeeding has important health benefits for babies. Babies may be brought into bed for breastfeeding or comforting, but should be returned to the crib/bassinet when the parent is ready to sleep.
  • Never let a baby fall asleep with someone who is smoking, tired or ill, has taken medication, drugs, alcohol or substances that cause drowsiness, or is extremely overweight.
  • The American Academy of Pediatrics recommends that babies be offered a pacifier at nap time and bedtime. Do not reinsert the pacifier if the baby refuses it or falls asleep. Do not coat the pacifier with anything sweet. The pacifier should be cleaned regularly. Delay pacifier use until after 1 month of age if the baby is breastfeeding.
  • Encourage "tummy time" when the baby is awake and observed by an adult. This will encourage motor development.
  • After the head position during sleep (place the baby with the head to one side for one week and then change to the other the following week). This will help reduce the risk of the baby developing a flat area on the back of the head.
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