Sudden infant death syndrome (SIDS) is the unexpected, sudden death of a child under age 1 in which an autopsy does not show an explainable cause of death.

SIDS rates have dropped dramatically since 1992, when parents were first told to put babies to sleep on their backs or sides to reduce the likelihood of SIDS. Unfortunately, SIDS remains a significant cause of death in infants under one year old. Thousands of babies die of SIDS in the United States each year.

The cause of SIDS is unknown, although there are several theories. Many doctors and researchers now believe that SIDS is not a single condition that is always caused by the same medical problems, but infant death caused by several different factors.

These factors may include problems with sleep arousal or an inability to sense a build-up of carbon dioxide in the blood. Almost all SIDS deaths occur without any warning or symptoms when the infant is thought to be sleeping.

SIDS is most likely to occur between 2 and 4 months of age, and 90% occur by 6 months of age. It occurs more often in winter months, with the peak in January. There is also a greater rate of SIDS among Native and African Americans.

The following factors increase the risk of SIDS:

• Babies who sleep on their stomachs
• Babies who sleep in the same bed as their parents
• Babies who have soft bedding in the crib
• Multiple birth babies
• Premature babies
• Babies with a sibling who had SIDS
• Mothers who smoke or use illegal drugs
• Teen mothers
• Short time period between pregnancies
• Late or no prenatal care
• Situations of poverty

SIDS affects boys more often than girls. While studies show that babies with the above risk factors are more likely to be affected, the impact or importance of each factor is not well-defined or understood.

There are no symptoms. Babies who die of SIDS do not appear to suffer or struggle.

Autopsy results are not able to confirm a cause of death, but may help add to the existing knowledge about SIDS. Autopsies may be required by state law in the event of unexplainable death.

Parents who have lost a child to SIDS are in tremendous need of emotional support. Because no cause is found for the infant's death, many parents suffer from guilt feelings.

These feelings may be aggravated by investigations of police or others who, by law, must determine the cause of death. Timing of a subsequent pregnancy is a concern for many parents after experiencing SIDS.

A member of a local chapter of the National Foundation for Sudden Infant Death Syndrome may assist with counseling and reassurance to parents and family members. See: SIDS support group

Family counseling may be recommended to help siblings and all family members cope with the loss of an infant.

If your baby is not moving or breathing, begin CPR and call 911. Parents and caregivers of all infants and children should be trained in CPR.

Revised American Academy of Pediatrics' (AAP) guidelines, released in October 2005, recommend the following:

Always put a baby to sleep on its back. (This includes naps.) DO NOT put a baby to sleep on its stomach. Side sleeping is unstable and should also be avoided. Allowing the baby to roll around on its tummy while awake can prevent a flat spot (due to sleeping in one position) from forming on the back of the head. 

Only put babies to sleep in a crib. NEVER allow the baby to sleep in bed with other children or adults, and do NOT put them to sleep on surfaces other than cribs, like a sofa.

Let babies sleep in the same room (NOT the same bed) as parents. If possible, babies cribs should be placed in the parents' bedroom to allow for night-time feeding.

Avoid soft bedding materials. Babies should be placed on a firm, tight-fitting crib mattress with no comforter. Use a light sheet to cover the baby. Do not use pillows, comforters, or quilts.

Make sure the room temperature is not too hot. The room temperature should be comfortable for a lightly-clothed adult. A baby should not be hot to the touch.

Let the baby sleep with a pacifier. Pacifiers at naptime and bedtime can reduce the risk of SIDS. Doctors think that a pacifier might allow the airway to open more, or prevent the baby from falling into a deep sleep. A baby that wakes up more easily may automatically move out of a dangerous position. However, do not force the infant to use a pacifier. Although pacifier use has been associated with dental problems and breast-feeding difficulties, researchers say the potential benefit (decreased SIDS risk) outweighs the risks. The AAP says that one SIDS death could be prevented for every 2,733 babies who suck on a pacifier during sleep.

Do not use breathing monitors or products marketed as ways to reduce SIDS. In the past, home apnea (breathing) monitors were recommended for families with a history of the condition.  But research found that they had no effect, and the use of home monitors has largely stopped.

Other recommendations from SIDS experts:

• Keep your baby in a smoke-free environment.
• Breastfeed your baby, if possible -- breastfeeding reduces some upper respiratory infections that may influence the development of SIDS.
• NEVER give honey to a child less than 1 year old -- honey in very young children may cause infant botulism, which may be associated with SIDS.

Until the nature of the disease is fully understood, complete prevention will not be a reality.

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