Newborns can make the cutest movements, noises, and faces while sleeping, and often you may notice they doze off with their mouth open.
It's often normal to see a newborn sleep with an open mouth, but aside from certain situations such as having a stuffy nose or crying, they should breathe through their nose when sleeping – even when their mouth is agape. They can breathe out of their mouth when they are crying or if they have a stuffy nose, but a newborn breathing from their mouth while sleeping regularly is less common.
In this article, we’ll discuss why a newborn sleeps with mouth open but breathes through nose most of the time and when do babies start breathing through their mouth more often. We’ll also explain what behaviors are normal, such as can newborns snore, and when to check in with your pediatrician about your baby’s sleep habits.
Is It Normal if a Newborn Sleeps with Mouth Open but Breathes Through Nose?
It’s normal see your newborn sleep with their mouth open and continue breathing from their nose.
Newborns breathe through their nose mainly due to anatomical reasons. This allows them to feed and breathe simultaneously. That’s why newborns are often considered “obligate nasal breathers” or “preferred nose breathers.” Their airway closes when they swallow.
Adults also breathe from their nose most of the time, too! Our nasal passage filters, warms, and humidifies air, making it safer and easier for our lungs to process. Nose breathing also prevents bad breath as well as dry mouth, which can affect our teeth, and gets us more oxygen. Some may sleep with their mouth open for other reasons, a preference, a temporary stuffy nose, or a condition that requires medical intervention.
If you notice your sleeping newborn is breathing through their mouth and breathing loudly, snoring, congested, or showing signs of discomfort, reach out to your healthcare provider. If your baby seems to be often mouth breathing when awake, it’s also important to reach out to your healthcare provider to identify why they are not innately breathing from their nose.
Is it normal if my infant sleeps with their mouth open?
Once your baby is out of the fourth trimester and starts to change their sleeping position or spend longer about of time in the deep sleep cycles you may start noticing your newborn sleeping with tongue out or mouth open because that’s how their face relaxes in sleep.
Similarly to a newborn, older child, or adult, if your baby has nasal congestion, mouth breathing may be common. As always, all infants under one-year-old should be placed to sleep on their back, even if it seems like they are congested or breathing from their mouth.
When do babies start breathing out of their mouth?
Babies start breathing out of their mouth as early as they need – as we mentioned, when they are crying or if they are congested. However, breathing through the nose is more common early in life to help a newborn safely and efficiently feed.
Remember, frequent or persistent mouth breathing could be a sign of something that requires medical attention.
What Causes Babies to Sleep with Their Mouth Open?
There are a few common reasons a baby may sleep with their mouth open. Remember, if you see your newborn sleep with open mouth but they breathe out of their nose, that’s likely just how they feel asleep. But, if you notice your newborn mouth breathing during sleep, it's important to address it with your healthcare provider.
Breathing and/or sleeping with mouth open causes:
- Newborn Active Sleep: Your baby will spend a lot of time in newborn active sleep, where they may move, grunt, cry, and flail in sleep. These movements or noises could cause their mouth to open, even though they are breathing from their nose.
- Relaxed: Sometimes a newborn sleeps with their mouth open but breathes through their nose because they have simply relaxed or are in a deep sleep and their mouth opens slightly.
- Nasal Congestion: Cold, allergies, or dry air, or rarely anatomical problems, can cause nasal blockage, pushing babies to breathe through their mouths. It can be hard to figure out how to get a sick baby to sleep but there are ways to keep them comfortable while ensuring safe sleep. If you’re wondering can a newborn snore, the answer is yes – especially if they have a stuffy nose.
- Deviated Septum: A structural difference in the nose can make nasal breathing harder – even from birth. This may mean your newborn sleeps with mouth open and breathes from mouth.
- Sleep Positioning: If your baby’s head tilts slightly during sleep, it may cause their mouth to fall open, even if they’re still breathing through their nose. Newborns can move a lot in their sleep due to reflexes. Make sure they are sleeping on their back though!
- Habitual Breathing: Sometimes babies develop the habit of mouth breathing. Speak to your healthcare provider on how to help them stop this habit.
- Baby Sleep Apnea: One symptom of baby sleep apnea is mouth breathing. Sleep apnea is a condition when your baby may pause in breathing for at least 20 seconds during sleep. Many babies outgrow it, but it’s important to be followed by your healthcare provider to ensure its resolve.
- Enlarged Tonsils or Adenoids: While more common in older children, enlarged tonsils or adenoids can cause swelling that blocks the nasal passage, making nasal breathing difficult. Issues with tonsils or adenoids should be discussed with your healthcare provider.
There are some rare medical conditions that affect the structure of the face and could cause mouth breathing. Speak to your healthcare provider if you have any concerns.
When to Worry About Newborn Sleeping with Mouth open
If your newborn sleeps with mouth open on occasion, such as when minorly congested, it’s likely nothing to worry about, especially if your baby is breathing comfortably.
However, if your newborn sleeps with mouth open and breathes from their mouth consistently, you should speak to your healthcare provider as there are potential risks that need to be addressed.
- Feeding Difficulty: If your baby struggles to breathe from their nose it could cause them to have difficulty getting the necessary nutrition they need. For example, newborns can breathe while sucking, but not while swallowing, which prevent food or liquid from accidentally going into their lungs during feeding. If they are unable to breathe while sucking, it becomes harder to feed. Keep in mind some premature babies have yet to develop their natural ability to suck, swallow, and breathe.
- Interrupted Sleep: Newborn mouth breathing may affect your baby’s sleep quality. This can be related to the quality of oxygen they receive when breathing out of their mouth versus nose. Sleep quality is important for them to reach their developmental milestones.
- Jaw and Facial Development Issues: Long-term mouth breathing in infancy may affect your newborn's facial structure and alignment.
- Dental Concerns: While newborns don’t yet have teeth, frequently mouth breathing can cause dry mouth, and less saliva leads to less natural protection for teeth and higher risk of cavity.
It’s always okay to reach out to your pediatrician if something doesn’t feel right. Your instincts are powerful – if you’re concerned, it’s worth having the conversation.
What to Do if Newborn Sleeps with Mouth Open Frequently
If your baby regularly sleeps with their mouth open, you may not need to do anything, unless they are also breathing out of their mouth regularly.
Supporting healthy sleep habits may reduce nighttime fussiness and help your baby rest more comfortably, whether they sleep with their mouth open or not!
Here are a few expert-recommended ways to encourage healthy sleep in your baby from the team at Smart Sleep Coach by PampersTM app. To get a personalized plan for building health sleep habits in your baby, take this free 3-minute sleep quiz.
- Use a Cool-Mist Humidifier: Avoiding dry air in your baby’s room and not overheating can help ease any congestion that may be causing a stuffy nose or keep their mouth moist if it falls open.
- Check for Allergens or Irritants: Sometimes dust, pet dander, or dry air are the sneaky culprits of your baby sleeping with mouth open.
- Shift Sleeping Position: All babies under one should sleep on their back, unless they are physically capable of rolling back and forth independently. If it seems your one of the sleeping with mouth open causes is a certain position, try adjusting them (while keeping them on their back, of course!)
- Clear Their Nose Safely: If your newborn has a stuffy nose, using saline drops and a nasal aspirator can help relieve congestion and promote nose breathing.
Never give an infant medication without speaking to your healthcare provider.
Final Thoughts
It's more common for a newborn to nose breathe, so it can sometimes be confusing to parents if their newborn sleeps with their mouth open. But, just like behaviors such as sleeping with arms up or twitching in sleep, it is ok for newborn to sleep with mouth open, but whether your baby is breathing through their nose or mouth should be monitored.
Anything new with a newborn can spark concern, and your newborn sleeping with an open mouth is no different. But in most cases, it’s simply a sign of deep sleep, temporary congestion, or just the way your baby’s body is adjusting to their new world.
Trust your instincts, stay curious, and enjoy the changes that occur during this new time of parenthood. And if something doesn’t feel quite right, reaching out to your healthcare provider is never the wrong move.
