SIDS
Babies who sleep on their stomachs are much more likely to die of sudden infant death syndrome (SIDS) than babies who sleep on their backs. To reduce your risk of SIDS, always place your baby on his or her back to sleep, for naps and at night. Place your baby on a firm sleep surface, such as on a Consumer Product Safety approved crib mattress. Never place your baby on pillows or sheepskins. Don’t let your baby sleep on a couch or soft mattress. Don’t overheat the baby during sleep. Do not allow smoking around your baby. “Tummy time” when the baby is awake will reduce the chance of molding of the baby’s head.
More Information:
sids.org