The safest sleeping position for a newborn is on their back.
Placing your newborn on their back to sleep is considered the safest position for your baby and the most effective thing you can do to lower your baby’s risk of SUID, according to the National Institutes of Health (NIH). It is suggested that you should continue to do just this at bedtime and naptime for the entirety of your baby’s first year.
Sleeping on their back allows babies to breathe easier and there is far less chance of them aspirating or choking on spit-up. When babies sleep on their back, their trachea lies on top of their esophagus which makes it virutally impossible for spit-up or vomit from the esophagus to pool in the trachea which would cause harm.
Unsafe Sleeping Positions for Babies
As we know babies do wiggle and roll and often many people have their own opinions on what positions are best.
Sleeping on their stomach is one of the most unsafe positions for a baby. It can ubstruct their airway which hinders their breathing. It also increases the chance of chocking on spit up and harming baby.
A baby that sleeps on their stomach can interfer with their ability to distribute heat causing overheating and therefore lead to SUID. However perhaps most importantly research suggests that babies sleeping on their stomach may be rebreathing their own oxygen, boosting their carbon dioxide levels and reducing their own oxygen levels. Taking in this stale air for babies would normally trigger their brain to wake and cry so that they can inhale fresh oxygen. However sometimes this wake-and-breathe signal misfires for babies which becomes very dangerous. It's been shown that an almost half of infants who die in their sleep are discovered on their stomachs.
Side sleeping is often a popular choice for babies as is can replicate the fetal postion. However side sleeping increases the chance of babies rolling onto their stomachs, increasing the chance of SUID. Placing a pillow or items to try keep baby from rolling on their stomach also causing it's own risks and can increase your babies chance of suffocation.
Research has shown that babies should be placed on their back while sleeping until their first birthday.