Sudden infant death syndrome (SIDS) is the unexplained death, usually during sleep, of a seemingly healthy baby less than a year old. SIDS is sometimes known as crib death because the infants often die in their cribs.
Although the cause is unknown, it appears that SIDS may be associated with abnormalities in the portion of an infant's brain that controls breathing and arousal from sleep.
Researchers have discovered some factors that may put babies at extra risk. They've also identified some measures you can take to help protect your child from SIDS. Perhaps the most important measure is placing your baby on his or her back to sleep.
A combination of physical and sleep environmental factors can make an infant more vulnerable to SIDS. These factors may vary from child to child.
Physical factors associated with SIDS include:
- Brain abnormalities. Some infants are born with problems that make them more likely to die of SIDS. In many of these babies, the portion of the brain that controls breathing and arousal from sleep isn't yet mature enough to work properly.
- Low birth weight. Premature birth or being part of a multiple birth increases the likelihood that a baby's brain hasn't matured completely, so he or she has less control over such automatic processes as breathing and heart rate.
- Respiratory infection. Many infants who died of SIDS had recently had a cold, which may contribute to breathing problems.
Sleep environmental factors
The items in a baby's crib and his or her sleeping position can combine with a baby's physical problems to increase the risk of SIDS. Examples include:
- Sleeping on the stomach or side. Babies who are placed on their stomachs or sides to sleep may have more difficulty breathing than those placed on their backs.
- Sleeping on a soft surface. Lying face down on a fluffy comforter or a waterbed can block an infant's airway. Draping a blanket over a baby's head also is risky.
- Sleeping with parents. While the risk of SIDS is lowered if an infant sleeps in the same room as his or her parents, the risk increases if the baby sleeps in the same bed — partly because there are more soft surfaces to impair breathing.
Although sudden infant death syndrome can strike any infant, researchers have identified several factors that may increase a baby's risk. They include:
- Sex. Boys are more likely to die of SIDS.
- Age. Infants are most vulnerable during the second and third months of life.
- Race. For reasons that aren't well-understood, black, American Indian or Alaska Native infants are more likely to develop SIDS.
- Family history. Babies who've had siblings or cousins die of SIDS are at higher risk of SIDS.
- Secondhand smoke. Babies who live with smokers have a higher risk of SIDS.
- Being premature. Both being born early and having low birth weight increase your baby's chances of SIDS.
Maternal risk factors
During pregnancy, the risk of SIDS is also affected by the mother, especially if she:
- Is younger than 20
- Smokes cigarettes
- Uses drugs or alcohol
- Has inadequate prenatal care
After losing a baby to SIDS, getting emotional support is critical. You may feel guilt as well as grief, and you'll be dealing with the mandatory police investigation into cause of death. You may find it comforting to talk to other parents whose lives have been touched by SIDS.
Your doctor may be able to recommend a support group in your area, or you can visit an online SIDS chat room. Talking to a trusted friend, counselor or clergy member may also help.
Communicate your feelings
If you can, let friends and family know how you're feeling. People want to help, but they may not know how to approach you.
As the baby's parents, be as open as possible with each other. Losing a child can put a terrible strain on a marriage. Counseling may help some couples understand and express their feelings.
Allow time for healing
Finally, give yourself time to grieve. Don't worry if you find yourself crying unexpectedly, if holidays and other celebratory times are especially difficult, or if you're tired and drained much of the time.
You're dealing with a devastating loss. Healing takes time.
There's no guaranteed way to prevent SIDS, but you can help your baby sleep more safely by following these tips:
Back to sleep. Place your baby to sleep resting on his or her back, rather than on the stomach or side. This isn't necessary when your baby's awake or able to roll over both ways without help.
Don't assume that others will place your baby to sleep in the correct position — insist on it. Advise sitters and child care personnel not to use the stomach position to calm an upset baby.
- Keep the crib as bare as possible. Use a firm mattress and avoid placing your baby on thick, fluffy padding, such as lambskin or a thick quilt. Don't leave pillows, fluffy toys or stuffed animals in the crib. These may interfere with breathing if your baby's face presses against them.
Don't overheat baby. To keep your baby warm, try a sleep sack or other sleep clothing that doesn't require additional covers. If you use a blanket, make it lightweight.
Tuck the blanket securely into the foot of the mattress, with just enough length to cover your baby's shoulders. Then place your baby in the crib, near the foot, covered loosely with the blanket. Don't cover your baby's head.
Have baby sleep in parents' room until age 1. Ideally, baby should sleep in the same room as the parents for the first year of life — or at least for the first six months — to decrease the risk of SIDS.
Baby should sleep alone in his or her own crib, bassinet or other surface designed for infants. Adult beds aren't safe for infants. A baby can become trapped and suffocate between the headboard slats, the space between the mattress and the bed frame, or the space between the mattress and the wall.
A baby can also suffocate if a sleeping parent accidentally rolls over and covers the baby's nose and mouth.
- Breast-feed your baby, if possible. Breast-feeding for at least six months lowers the risk of SIDS.
- Don't use baby monitors and other commercial devices that claim to reduce the risk of SIDS. The American Academy of Pediatrics discourages the use of monitors and other devices because of ineffectiveness and safety issues.
Offer a pacifier. Sucking on a pacifier at naptime and bedtime may reduce the risk of SIDS. One caveat — if you're breast-feeding, wait to offer a pacifier until your baby is 3 to 4 weeks old and you've settled into an effective nursing routine.
If your baby's not interested in the pacifier, don't force it. Try again another day. If the pacifier falls out of your baby's mouth while he or she is sleeping, don't pop it back in.
Oct. 28, 2016
- Sudden infant death syndrome. American Lung Association. http://www.lung.org/lung-disease/sudden-infant-death-syndrome/. Accessed March 14, 2014.
- Task Force on Sudden Infant Death Syndrome. SIDS and other sleep-related infant deaths: Updated 2016 recommendations for a safe infant sleeping environment. Pediatrics. 2016;138:e20162938.
- Corwin MJ. Sudden infant death syndrome. http://www.uptodate.com/home. Accessed March 14, 2014.
- Wong CA, et al. American Indian and Alaska Native infant and pediatric mortality, United States, 1999-2009. American Journal of Public Health. 2014;104:S320.