Baby Sleeping on His Side? How to Encourage Your Little One to Sleep on His Back

The first rule of safe baby sleep 101 is that you should always, always place your baby to sleep on his back, from the moment he’s born, to reduce the risk of sudden infant death syndrome (SIDS). 

Still, it's no secret that babies sometimes fuss when they’re on their backs. And if you've ever watched tummy time spontaneously turn into naptime, you might have noticed your baby seems more content snoozing on his stomach.  

Indeed, belly sleeping seems to be the preferred position for many babies. Little ones may be less likely to startle and wake themselves up — possibly because it feels more secure and cozier snuggling up against the mattress. 

But even though your baby might be more comfortable snoozing on his tummy, it isn’t safe until he’s strong enough to roll himself over onto his stomach himself. Here’s why it’s so important for your baby to sleep on his back, plus tips to encourage back sleeping.

Baby sleeping on side vs. back

Is it safe for babies to be put down to sleep on their sides or tummies? The short answer is no. You should put your baby to sleep on his back from birth and continue to do so until he is 1 year old. While the incidence of SIDS is highest for the first six months, the recommendation of "back to sleep" applies for the whole first year.

Even with this basic message down-pat, you might wonder why side and tummy sleeping positions are so risky before a baby can roll himself over. Here’s a look at the potential dangers.

Keep in mind SIDS is still very rare, with an incidence rate of 0.035 percent, or 35 deaths in 100,000 live births, according to the Centers for Disease Control and Prevention (CDC). However, stomach sleeping increases the risk of SIDS up to 12.9 times, research shows. Side sleeping, too, makes SIDS more likely.

Infants tend to sleep more deeply on their stomachs, which experts suggest may mute their arousal responses. That could prevent them from waking up during normal episodes of sleep apnea, so they can resume normal breathing patterns. 

Stomach or side sleeping can also set the stage for "rebreathing," where a baby breathes in his own exhaled air, causing his oxygen levels to drop and his carbon dioxide levels to rise. Rebreathing might be even more likely to happen if a baby is sleeping on a soft mattress or with blankets, pillows or stuffed animals near his face.

Finally, stomach or side sleeping can also make it harder for your baby’s body to release excess heat. That can lead to overheating — another risk factor that makes SIDS more likely.

How to get a baby to stop sleeping on his side

If it seems like your newborn just can’t sleep comfortably on his back, he’s not alone. Many babies seem to feel more secure snoozing on their bellies or their sides.

If that’s the case, there are things you can do to try to keep your baby both happy and safe while he rests. From the day you bring him home, try these strategies for getting your baby to sleep on his back (and keep him in that position!).

Swaddle your baby

A cozy burrito-style wrap will help give your baby the security he’s craving from sleeping on his tummy. Swaddling with a blanket is easy once you get the hang of it, but you can also sidestep the folding and tucking altogether by opting for a zipper or Velcro swaddle wrap.

A few important tips to keep in mind for safety: Make sure your baby’s room is cool enough to be comfortable in the extra layers, since overheating is another risk factor for SIDS.

Also know that you’ll need to stop swaddling (or switch to a swaddle-sack hybrid or a sleep sack, which can’t be kicked off) as soon as your baby shows signs of trying to roll. That typically happens around ages 3 to 4 months, but it can be as young as 2 months for some babies.

Offer a pacifier

Give your baby a binky when you put him down for his nap or to sleep at night. Having something to suck on can be soothing, plus it's harder for babies to keep pacifiers in their mouths if they roll onto their tummies or sides, so it's a tactic that often works well at keeping them sleeping on their backs.

Skip the positioner

Steer clear of wedges, rolled up blankets or other positioners placed on your baby’s mattress. Even though some of these products might claim to prevent SIDS, they actually pose a serious suffocation risk.

Ease him into it

Train your baby to be more comfortable sleeping on his back by rocking him until he's drowsy, then transferring him to the crib and putting him down on his back. 

Stick with it

Consistency is key when it comes to any sleep routine. So while it might take some time and persistence, even if it seems like your newborn just won't sleep on his back, eventually he’ll get used to the position — especially if he’s never known another way to snooze.

Know when to call the doctor

The vast majority of babies adjust to sleeping on their backs, even if they aren’t big fans at first. But talk with the pediatrician if your baby fusses every time you put him to sleep on his back. It’s rare, but there are some physical and anatomical reasons a baby may be uncomfortable sleeping on his back that your pediatrician should rule out first.

Is it okay if baby rolls onto his stomach while he's sleeping?

It can be nerve-wracking to peer into the crib or bassinet and see that your baby has wriggled onto his tummy or side — especially the first time. But don’t panic: It’s okay for your baby to roll over in his sleep, and if he does, you don’t have to move him.

Most babies master the art of rolling over between the ages of 3 and 6 months. And once they do, many decide that they prefer to sleep on their stomachs or sides.

Thankfully, you don’t have to worry about repositioning him onto his back. Once your little one is capable of rolling and changing positions easily, he’s strong and agile enough to protect himself against the factors that make tummy sleeping dangerous for younger babies.

In short, babies who can roll themselves over and back are at a significantly decreased risk of SIDS, which experts believe is because babies with that ability have also developed the maturity to sense trouble during sleep and move into a safer position.

That said, even if your baby changes position at night, you should continue putting him down to sleep on his back until his first birthday. (If he wants to flip over after you put him down, that’s up to him!)

And of course, you should continue sticking with other safe sleep guidelines — like putting your baby down on a firm, flat surface and keeping the crib free of any other objects, including blankets, pillows, bumpers, loose-fitting sheets and stuffed toys.  

It’s normal for your baby not to love sleeping on his back, but it’s the only safe way for him to snooze. Put your baby to sleep on his back every time, and take other steps to help him feel cozy and secure like swaddling him or offering a pacifier. He’ll eventually adjust, and you’ll both be able to rest easier.