Research on Sudden Infant Death Syndrome (SIDS) (cont.)

The Institute maintains a Web site for the Back to Sleep campaign, which outlines the history of the campaign and of SIDS in the United States, provides general information about SIDS and ways to reduce the risk of SIDS, and offers free materials for learning more about SIDS risk reduction. You can also call 1-800-505-CRIB (1-800-505-2742) to order free Back to Sleep materials.

NICHD Research on SIDS

The NICHD has been working to reduce the number of SIDS deaths, both through the Back to Sleep campaign, and through research into the causes and features of SIDS.

Recent research suggests that many SIDS babies are born with brain defects that may increase their risk of SIDS. Studies of SIDS victims show that many SIDS infants have an abnormality in a network of neurons in the brainstem that are involved in the developing and controlling blood pressure and breathing, temperature regulation, and sleep and waking. Although this brain defect may not be the sole cause for SIDS, researchers have some ideas about how the brain problem may be involved in SIDS:

  • Research suggests that stomach sleeping and soft bedding increase an infant's risk of re-breathing his or her own exhaled air. When an infant is sleeping in its stomach, the exhaled air (carbon dioxide) may get trapped between the infant's face and the bedding. When the infant breathes exhaled air, the oxygen level in the baby's body drops and the carbon dioxide level rises, which may lead to SIDS. If a baby is re-breathing exhaled air and not getting enough oxygen, the brain usually triggers the baby to wake up and cry. This action changes the baby's breathing and heart rate, making up for the lack of oxygen. But, a baby with a flaw in the brainstem might lack this method of protection and may be at greater risk for SIDS.
  • Another theory is that stomach sleeping and/or soft bedding, such as quilts and comforters, increases the risk of overheating. If the baby's face or head is covered by bedding, the baby will begin to overheat. The brain usually triggers the baby to wake-up and move and free his or her head. A baby with a flawed brainstem however, might lack this method of protection and may be at greater risk for SIDS.
  • Babies born with defects in other parts of their brains or bodies may also be at greater risk for SIDS. These defects might be the result of prenatal exposure to a toxic substance. For example, smoking during pregnancy can reduce the amount of oxygen the growing baby receives, making it more susceptible to conditions of low oxygen later in life.

A recent study also found a greater risk of SIDS among babies who were regularly placed on their backs to sleep, but were switched to the less-familiar stomach sleeping position.

Other research, funded by the NICHD, helped to identify risks for SIDS among Native American communities. The findings of this study have been vital in shaping the campaign's outreach project for American Indian communities, in hopes of finding ways to reduce the risk of SIDS.

Source: National Institutes of Health (

Last Editorial Review: 12/3/2004