Sudden Infant Death Syndrome

Also known as: SIDS, crib death, cot death.

What is sudden infant death syndrome?

SIDS (sometimes called crib or cot death) is the term used to describe the unpredictable sudden death of a normal infant less than 1 year of age (usually between 1 month and 1 year), which remains unexplained after all causes of death have been ruled out. Most of these infants die aged < 6 months.

What causes sudden infant death syndrome?

The exact cause is unknown however there appears to be a number of risk factors which make place an infant at greater risk. A combination of brain and environmental factors are important.

These include:

• babies who have other babies in the family who have died with a SIDS diagnosis
• abnormalities in the area of the baby’s brain that controls breathing and arousal from sleep
• maternal smoking
• alcohol and/or drug use during pregnancy (or baby’s exposure to secondhand smoke)
• young mothers (under 20 years of age)
• poor maternal prenatal care
• respiratory infection that cause breathing problems
• low birth weight or premature babies
• overheating
• baby sleeping on the stomach or side
• sleeping on a soft surface or sleeping with parents

What are the symptoms of sudden infant death syndrome?

Sudden infant death syndrome is fatal. There are typically no symptoms or warning signs before it occurs.

What are sudden infant death syndrome care options?

While there is no treatment for SIDS, preventive measures to reduce all risk factors (particularly placing baby on the back to sleep, not overheated, in a parents’ room, in their own bare crib without pillows or toys, and on a firm mattress), plus breastfeeding, encouraging the use of a pacifier and immunizing the baby, may all decrease the risk of SIDS in your baby.

After losing a baby to SIDS, parents require time, and emotional support to cope with the devastating tragedy of losing a baby.

Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: September 16, 2025 12:27 PM