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Baby sleeping face down with butt in the air in a crib, in a story answering the question, why do ba...
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Here’s Why Your Baby Sleeps Like A Roast Chicken

Don’t lose sleep over this odd (and super adorable) position.

by Cat Bowen and Katie McPherson
Updated: 
Originally Published: 

Parents who learn about safe sleep for their newborn know all about putting their little one flat on their back to fall asleep. So, as your tiny babe gets bigger and more mobile, it can stress you out to find your baby sleeping on their belly facing the mattress, though you have to admit, it’s pretty cute. So, why do babies sleep with their butts in the air? Why does your baby keep assuming this position — in which they basically look like a roast chicken — overnight, and is it unsafe?

Why do babies sleep with their butts in the air?

It turns out there are several possibilities for why babies sleep in child’s pose. And Dr. Sophie Shaikh, M.D., board-certified pediatrician and director of Duke Newborn Nurseries at Duke University Hospital, tells Romper in an interview that there are a few popular theories about why your baby loves sleeping froggy style. “There doesn’t seem to be concrete scientific evidence to really explain it for sure,” she explains. “It may feel reminiscent of the fetal position that they are tucked into in the womb, and makes them feel comfortable and secure. Others think that while little ones are learning to sit and crawl, this is a natural position for them to flop forward into once they run out of steam, and they decide to just sleep how they fall.”

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Babies like to be tucked up as they are in the womb, notes Dr. Harvey Karp, M.D., in The Happiest Baby on the Block. That’s why swaddling is so effective. When babies realize they can mimic this themselves, either by happenstance of crawling or rolling over, it makes sense they’d be comfortable enough to doze off in that position.

Shaikh’s theory about babies ending up in this position when they get tired from physical exertion (sitting up can take great effort) also makes sense. You’ll notice that your baby sleeping on their knees looks remarkably similar to the position they assume both as they’re learning to crawl and after they begin crawling. Many babies get into that position and rock back and forth for a long time before they even begin to crawl. But when the American Academy of Pediatrics (AAP) warns parents that babies must always be placed to sleep on their backs to minimize the risk of SIDS, it’s understandable to wish they’d just hold still for once, if only in their sleep. If you find repositioning your baby is pointless and they just flop back onto their tummies, try not to stress.

When do babies stop sleeping with their bums in the air?

If you’re already stressed about when your baby might want to sleep booty up, chances are you’d also like to know when they cut it out too. There’s an average age when babies are able to roll over and sleep on their tummies. As for flipping back over, it depends on their personal preference.

“Not every baby wants to sleep that way, but some certainly love to flip over,” says Dr. Erinn Schmit, M.D., pediatrician at Children’s of Alabama. “Usually babies aren’t rolling both ways until about 5 to 6 months of age. As far as when they might go back to sleeping on their backs, it’s just baby dependent if it’s something that they want to do or not. I agree that younger infants tend to like sleeping on their tummies, whereas toddlers don’t seem to do that quite as often.”

Is it safe for my baby to sleep sleep with their butt in the air?

Schmit emphasizes that there’s no specific age where it’s safe for every baby to sleep butt in the air. Shaikh says it’s OK for your baby to sleep on their knees with their bottom up under one condition:

“If your baby turns onto their belly or side during sleep, it’s safe to leave them in that position if they’ve mastered rolling both ways: belly to back and back to belly,” she says. “If you find that they have managed to get onto their side or belly before that point, you should gently move them onto their back. Even once they are able to roll, it’s important to put your baby down on their back for sleep until they are 1 year old. It’s OK to let them stay on their belly if they turn that way by themselves, but it’s recommended to always start them off on their back.”

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Babies who sleep exclusively on their backs tend to reach motor milestones, like rolling and crawling, a little slower than kids sleeping on their side or bellies, according to the European Journal of Applied Psychology. That may tempt some parents to let their littles snooze face down to help them catch up, but Shaikh notes any developmental differences are minor.

“We do know that babies who are put ‘back to sleep’ take slightly longer to reach their motor milestones than kids that sleep either on their bellies or sides, likely because belly sleeping increases upper body strength that infants need for some of the motor movements,” she says. “However, it’s just slightly longer and still within the normal range. ‘Back to sleep’ positioning doesn’t cause any abnormal delays in reaching the milestones. And doing tummy time while the infant is awake is great for working on those motor skills.”

Doing tummy time while your baby is awake, and you can supervise, is all it takes to help them strengthen key neck and chest muscles. And don’t worry too much about finding newborns flipping over in their sleep. “Don’t stay up all night worrying about your 6-week-old flipping onto their belly,” says Dr. Randy Thornton, M.D., a pediatrician at Jacksonville Pediatrics and Wolfson Children’s Hospital of Jacksonville. “They should not be able to roll over much earlier than 4 months old, but if you find them that way, flip them over. I’ve never seen it happen so I don’t want parents to lose sleep over it. If they start to roll over, generally they have grown out of the risk of SIDS.”

Babies are hilarious, and babies sound asleep with their booties in the air are just precious. And basically, once they can get themselves into the froggy position, they can get themselves back out if they need to. Take some pictures, get some sleep, and see if this new position helps your baby get better rest, too.

Study referenced:

Hewitt, L., Kerr, E., Stanley, R. M., & Okely, A. D. (2020). Tummy time and Infant Health Outcomes: A systematic review. Pediatrics, 145(6). https://doi.org/10.1542/peds.2019-2168

Experts:

Dr. Sophie Shaikh, M.D., board-certified pediatrician and director of Duke Newborn Nurseries at Duke Regional Hospital and Duke University Hospital

Dr. Erinn Schmit, M.D., pediatrician at Children’s of Alabama

Dr. Randy Thornton, M.D., pediatrician at Jacksonville Pediatrics and Wolfson Children’s Hospital of Jacksonville in Florida

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