The sudden, unexplainable death of a baby under 1 year old is called sudden infant death syndrome (SIDS). Also known as “crib death,” SIDS strikes about 3,000 infants in the United States every year. Typically, a death from SIDS happens without warning between midnight and 8 a.m. when a baby is thought to be asleep, and the baby dies very quickly, without any apparent suffering. Ninety percent of SIDS deaths involve children under 6 months old. The most vulnerable age appears to be between 2 months and 4 months old. Male babies are at slightly greater risk.

Risk Factors

Of the risk factors for SIDS, one has become commonly known: putting a baby to sleep on its stomach. Several environmental factors seem to play a role as well: putting the baby to sleep with soft bedding, putting the baby to sleep in a room that’s too warm, and smoking around the baby. Secondhand smoke and overheating cause arteries to shrink and blood flow to slow. There are numerous other risk factors. A baby is at greater risk for SIDS if he or she:

• Is African American or Native American
• Was premature
• Had a low birth weight
• Was part of a multiple birth (for instance, twins or triplets)
• Has a respiratory infection
• Had a sibling who died from SIDS.

  Research shows that certain characteristics of mothers may increase their baby’s risk of SIDS, too. If a woman smokes during and after her pregnancy, her baby is three times more likely to die from SIDS. A baby is also at greater risk if his or her mother is younger than 20 during her first pregnancy, has had pregnancies too close together, or got late or no prenatal care. Low weight gain during pregnancy, anemia and a habit of consuming more than 400 milligrams of caffeine a day during pregnancy may also increase the risk of having a baby who succumbs to SIDS.