FACT: Many babies have slept on their stomachs and survived, but that doesn’t mean that was the safest way for them to sleep.  For reasons that doctors are still trying to understand, some babies who sleep on their stomachs become unable to take a breath when needed. This can cause them to suffocate because of their inability to change position and take a breath. It is also possible that stomach sleeping can increase an infant’s risk of “rebreathing” his or her own exhaled air, especially if the infant is in an environment with soft bedding near the face. As baby breathes the exhaled air, the oxygen level in the body can drop, carbon dioxide can accumulate and the baby can experience a lack of oxygen.
Babies are safest sleeping on their back for every sleep – at nap time and at night time.