How your baby breathes while they sleep matters just as much as how long they sleep.
Newborns spend most of their day asleep, and that sleep is busy work. It's when the brain organizes itself, when growth hormone does its job, and when the nervous system learns how to settle. So when parents ask me "is my baby sleeping enough?" I always want to ask a second question too: how is your baby sleeping?
This isn't meant to make you lie awake watching your baby breathe (you're tired enough already ). It's meant to give you a few simple things to notice, so that if something is off, you can catch it early, when it's often the easiest to support.
Babies are built to breathe through their nose
Newborns are designed to be nose breathers. When everything is working the way it's meant to, a sleeping baby has their lips gently closed, their tongue resting up against the roof of their mouth, and quiet, easy breaths moving through the nose.
That resting tongue position is doing more than you'd think. The tongue up on the palate helps shape the palate as it grows, supports the airway from the inside, and is the same foundation your baby uses for a deep, effective latch. Feeding and breathing share the same real estate, so when one is struggling, the other often is too.
Nose breathing also filters and warms the air, and it helps the body stay in that calm, rest-and-digest state that deep sleep depends on.
When a baby sleeps with their mouth open, it's usually a sign their body is working harder than it should to get air in. Some common reasons I see in practice:
Nasal congestion (this one is common and often temporary)
Low tongue resting posture, sometimes related to oral restrictions like a tongue tie
Tension through the jaw, neck, or whole body, often after a long or complicated birth
Low muscle tone, or a baby who is still working on head and neck control
Babies who spent time in the NICU or had breathing support early on
An open mouth during one stuffy night is not a crisis. An open mouth most nights, especially paired with noisy breathing, is worth a closer look.
When your baby tips their head back, they may be opening their airway
Here's one I love teaching parents to spot, because once you see it, you can't unsee it.
Some babies sleep with their head tipped way back and their chin pointing up, almost like they're looking at the headboard. Parents often tell me "oh, that's just how she likes to sleep." And sometimes it is! But very often, that extended head position is your baby's clever, instinctive way of opening up their airway.
Think about what a lifeguard does for someone who isn't breathing well: tilt the head back, lift the chin. Your baby's body knows that same trick. Extending the neck pulls the tongue and soft tissues forward and away from the back of the throat, which makes more room for air to move.
So a baby who consistently sleeps in extension is often telling us something like: "breathing is a little hard for me, so I found a workaround." That workaround is smart, and it's also information. It can come along with:
Mouth breathing or snoring
Restless sleep, lots of wiggling and repositioning
Sweaty heads or backs during sleep
Frequent waking, or short naps that never seem to fully restore
Strong arching or a preference for extension during feeds and while awake
Over time, living in extension can also feed into body tension, a preference for turning one way, and feeding challenges, because the muscles that help a baby tuck, latch, and swallow work best from a more neutral, gently flexed position.
Why this matters later: sleep, breathing, and behavior
This is the part that surprises most parents. How a baby breathes during sleep in the first year or two can connect to how they focus, regulate, and behave years down the road. 🧠
In 2012, researcher Karen Bonuck and her team published a large study in Pediatrics that followed more than 11,000 children in the UK from infancy to age 7. Parents reported on snoring, mouth breathing, and pauses in breathing at several points starting at 6 months old. Together, those signs are called sleep-disordered breathing.
What they found:
Children with sleep-disordered breathing were 40 to 100% more likely to have behavioral challenges by age 7.
The biggest increase was in hyperactivity, but emotional difficulties, conduct challenges, and trouble with peers all went up too.
Even babies whose symptoms peaked early (around 6 or 18 months) and then went away still had a 40 to 50% higher chance of behavioral challenges at age 7.
That last point is the one I want every parent to hear. Infancy is a window of rapid brain development and the time when babies need the most sleep. What happens with breathing during this window seems to matter, even if it resolves on its own later.
Why would breathing affect behavior? The researchers point to a few reasons. Interrupted breathing fragments sleep, so the brain doesn't get its full restorative time. It can also shift oxygen and carbon dioxide levels in the part of the brain responsible for attention and self-regulation. A chronically under-rested nervous system has a harder time settling, focusing, and handling big feelings.
A really important note: this study found an association, and behavior is shaped by many, many things. An open-mouthed sleeper is not destined for anything. What this research gives us is a reason to stop saying "wait and see" and start paying gentle attention early, when support is simple and the brain is incredibly responsive.
What to notice tonight
You don't need any special equipment for this. Next time your baby is in a deep sleep, take a quiet minute and look for:
Mouth: Are their lips closed, or is the mouth hanging open?
Sound: Is breathing quiet, or do you hear snoring, snorting, or whistling?
Head position: Is the head in a fairly neutral position, or tipped far back with the chin pointing up?
Effort: Does breathing look easy, or do you see the belly or chest working hard, or the skin pulling in at the base of the neck or between the ribs?
Rest: Does your baby stay settled, or are they constantly wiggling, sweating, or waking?
A quick phone video of your sleeping baby is one of the most helpful things you can bring to an appointment. 📱 It shows us what we can't see in the office.
Please call your pediatrician right away, or 911 in an emergency, if you ever notice pauses in breathing, gasping, or a blue or gray color around the lips. Those signs need medical eyes immediately.
And as always, keep following safe sleep guidelines: baby on their back, on a flat, firm surface, with nothing propping the head or neck. The goal is never to force your baby's head into a certain position while they sleep. The goal is to understand why they're choosing that position and support the root of it while they're awake.
What helps, and how we can support you
The good news is that babies are wonderfully adaptable, and the earlier we look, the more we can do. Depending on what's driving the mouth breathing or extension, support might include:
A full-body look, not just the mouth. Tension in the neck, jaw, ribs, or pelvis can all change how a baby holds their head and tongue.
Craniosacral therapy and gentle bodywork to release tension and give the tongue, jaw, and neck room to move the way they're meant to.
Physical or occupational therapy to build head and neck control, encourage flexion, and help your baby find more comfortable positions while awake.
Feeding support with an IBCLC, since latch, suck, swallow, and breathing are all connected.
A thorough oral function assessment, and a referral to a trusted provider if a tongue tie or airway concern needs a medical evaluation.
Coordinating with your pediatrician or an ENT when congestion, snoring, or breathing pauses need their expertise.
At Be Well Baby, this is exactly the kind of puzzle our team loves. Our PTs, OTs, and lactation consultants look at your baby as a whole little person, because breathing, feeding, sleep, and development all work together.
If your baby is a mouth breather, a head-back sleeper, or a restless sleeper who never seems truly rested, you don't have to wait and see. Book a visit with our team in Multnomah Village, or call or text us at (971) 351-2714. Bring that sleepy video, and let's figure it out together. ✨
References
Bonuck K, Freeman K, Chervin RD, Xu L. Sleep-disordered breathing in a population-based cohort: behavioral outcomes at 4 and 7 years. Pediatrics. 2012 Apr;129(4):e857-65. doi: 10.1542/peds.2011-1402. Epub 2012 Mar 5. PMID: 22392181; PMCID: PMC3313633.
Albert Einstein College of Medicine press release on the study (EurekAlert, 2012)
