What Is SIDS? Causes, Risk Factors and Prevention Steps

Sudden infant death syndrome, or SIDS, is every parent's quiet fear. Understanding what is known can help you focus on the steps that matter. This article summarises MedlinePlus and American Academy of Pediatrics information. It is general education and cannot tell you about your own baby.

What is SIDS?

MedlinePlus describes SIDS as the sudden, unexplained death of a baby younger than one year. It is sometimes called crib death, because many affected babies are found in their cribs. MedlinePlus says it is the leading cause of death for children between one month and one year of age, and most cases happen between one and four months. The cause is not known.

The AAP adds that sleep-related deaths include SIDS as well as accidental suffocation and strangulation, and that no method can guarantee SIDS will not happen. A safe sleep environment does lower the risk of all sleep-related deaths.

Known risk factors

MedlinePlus lists several factors linked with a higher risk: being born prematurely, being male, and belonging to certain groups, including African American and American Indian or Alaska Native babies. Many of these cannot be changed, which is why the steps below are so useful for every family.

The AAP also says bed sharing is more dangerous when the baby is under 4 months, small or born early, when a parent has used alcohol or drowsiness-causing medicines or drugs, or when anyone smokes or vapes.

Steps that help lower the risk

MedlinePlus and the AAP point to these practices:

1. Back to sleep. Place your baby on the back for every sleep, including naps. Tummy time is only for when the baby is awake and watched.
2. Share the room, not the bed. Keep your baby in your room for at least the first 6 months, on a separate surface such as a crib or bassinet placed close to you.
3. Firm surface. Use a firm mattress with a fitted sheet.
4. Clear sleep space. Keep soft objects and loose bedding out of the sleep area.
5. Breastfeed. The AAP says breast milk offers protection, which grows the longer feeding continues.
6. Do not overheat. Keep the room at a temperature comfortable for an adult. The AAP suggests dressing your baby in one more layer than an adult would wear.
7. Keep the air smoke-free. Do not smoke during pregnancy and do not let anyone smoke near the baby.

The AAP also notes that offering a pacifier at sleep times, going to routine pregnancy care and well-child visits, and keeping vaccines up to date are linked with lower risk.

What does not help

The AAP warns that products claiming to prevent SIDS have no proven benefit. Home heart or oxygen monitors do not reduce SIDS risk and should never replace safe sleep practices. Swaddling does not reduce the risk either.

Why the same advice applies to every baby

Because the cause of SIDS is unknown, doctors cannot say which baby will be affected. That is why the guidance is the same for all families. The AAP says these recommendations apply to babies up to 1 year old, and the risk of sudden death in sleep is lower when the whole sleep environment is safe, not just one part of it. Changing even one habit, such as moving a sleeping baby from a sofa to a cot, can matter. It also helps to share the advice with grandparents, babysitters and anyone else who may put your baby down to sleep.

Where to find support

If a family loses a baby, the grief can be overwhelming. Reach out to your doctor or a local support service. If you are struggling in the days after a loss, or feel unable to cope, ask for help right away.

When to see a doctor

Talk to your baby's pediatrician if you have questions about sleep positions, feeding or the sleep space, or if your baby has breathing pauses, trouble feeding or unusual sleepiness. In an emergency, such as a baby who is not breathing, cannot be woken or has turned blue, call your local emergency number (112 in India, 911 in the United States).