Laryngomalacia (Floppy Larynx) — the most common cause of newborn stridor
Why your baby makes a high-pitched noisy sound when breathing in. What's normal, what to watch for, when it settles, and the small minority who need ENT review.
- Last reviewed
- Sources cited
- 4 sources
- Author
- Dr Jubal John, FRACP
- Category
- medical guides
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Take-home
Laryngomalacia is the most common cause of noisy breathing in newborns, a soft, high-pitched inspiratory stridor that often appears in the first few weeks, peaks around 4-8 months, and settles on its own by 12-18 months in the great majority of babies. Most babies with laryngomalacia feed well, grow normally, and need no treatment beyond reassurance and watchful waiting. A small minority, usually with feeding difficulties, poor weight gain, or significant pauses in breathing, need ENT (ear, nose and throat) review and occasionally a small day-stay procedure called supraglottoplasty.
What is laryngomalacia?
The larynx is the voice box, the entrance to the airway, sitting at the back of the throat. In newborns, the cartilage and tissue around the larynx is normally still soft and pliable. In laryngo-malacia (literally “soft larynx”), some of those tissues are floppier than usual, usually the epiglottis and the arytenoid cartilages above the vocal cords. Each time your baby breathes in, they partially collapse inward.
That brief inward collapse narrows the airway momentarily and creates the characteristic noisy inspiratory sound.
It is:
- Common: the most frequent congenital anomaly of the larynx and the leading cause of stridor in infants; only a smaller subset are clinically significant
- Congenital: present from birth, though the noise often only becomes audible at 1-4 weeks of age as feeding intensifies
- Self-limiting: the cartilage stiffens with growth and most cases resolve by 12-18 months
- Not painful or distressing for the baby in mild forms, most babies sleep, feed and grow normally
The sound: what to listen for
The classic laryngomalacia sound is:
- High-pitched: almost a squeak or a soft “crow”
- Heard mostly on breathing in (inspiration), not on breathing out
- Worse when:
- Lying on the back
- Feeding (especially toward the end of a feed)
- Crying or upset
- Asleep, particularly in deep sleep
- With a cold or upper respiratory infection
- Better when:
- Held upright
- Tummy time (when the airway opens)
- Calm and awake
A baby who sounds rattly and noisy on the chest, but whose chest itself moves comfortably, is the typical picture.
Stridor vs other newborn breathing sounds
- Stridor (laryngomalacia, croup, vocal-cord problems): a higher-pitched, upper-airway sound, usually on breathing in
- Wheeze (bronchiolitis, asthma): a whistling lower-airway sound, usually on breathing out
- Stertor (snoring sound): comes from the nose and throat above the voice box; often blocked nasal passages
- Grunting: a short, rhythmic sound at the end of each breath; in newborns this is a red flag for working harder to breathe and warrants urgent review
If you’re not sure which one your baby is making, recording a short video on your phone (with the baby uncovered to the chest if possible) is the single most useful thing you can do. Bring it to the appointment.
When it appears, peaks, and settles
The typical timeline:
- Birth – 4 weeks: often quiet at first; the larynx isn’t yet under high airflow
- 2 – 8 weeks: the noise becomes audible as feeds intensify and the baby is awake more
- 4 – 8 months: peak, the noise is at its most prominent
- 8 – 18 months: gradual resolution as the cartilage stiffens with growth
- By 2 years: almost all babies are completely silent on inspiration, with normal feeding and growth
A small number of babies have stridor that persists past 18 months or that is severe enough at peak to warrant intervention, see When ENT review is needed below.
When to seek help: the short version
Green — usually fine
Green: manage at home, expect resolution
- High-pitched sound on breathing in, worse when supine or feeding
- Baby is otherwise well, feeding fine, gaining weight, sleeping reasonably
- The sound peaks around 4-8 months and gradually settles
- Mild reflux or some spitting up at the end of feeds (common alongside laryngomalacia)
Amber — be alert
Amber: see your GP, paediatrician or MCH nurse
- The sound is becoming more prominent week by week
- Feeds are taking longer than 30 minutes or your baby tires before finishing
- Weight gain has slowed
- Frequent vomiting or back-arching with feeds (significant reflux)
- A persistent dry cough or hoarse cry
- Recurrent chest infections
Red — act now
Red: call 000 or go to your nearest emergency department
- Sudden onset of severe noisy breathing (think inhaled object, severe croup, or anaphylaxis, not laryngomalacia)
- Pauses in breathing lasting longer than 20 seconds, or any pause with a colour change
- Blue lips, blue tongue, or pale grey skin, at any time
- Severe work of breathing: nostrils flaring with each breath, dipping above the breastbone, ribs sucking in below the chest, head bobbing, see the respiratory distress signs on the bronchiolitis guide for what these look like
- Baby unwell, floppy, very hard to wake, or feeding very poorly
Why it usually doesn’t need treatment
For most babies with laryngomalacia (around 80-90% in the Thompson 2012 review), the noise sounds dramatic but the baby is doing the things that matter:
- Feeding well: taking a normal volume, in a normal time
- Growing: tracking along their weight centile
- Sleeping reasonably: wakes for normal feeds, settles back, no concerning pauses
- Generally happy when held upright: alert, smiling, engaging
In that picture, the right management is watchful waiting: regular weight checks, an explanation for the family, a video for review if the noise changes, and time. The cartilage stiffens, the noise settles. No medication speeds this up. No specific position fixes it (though upright after feeds tends to help).
Common questions
“Should we elevate the cot?”
Cot mattresses should stay flat, firm and level: see the safe sleep guide. The “elevate the head of the cot” advice you may read online is not best practice and slightly increases the risk of the baby slipping into a head-down position. Holding your baby upright for 20-30 minutes after a feed is fine and often helpful; the cot itself stays flat.
“Does reflux make it worse?”
Some babies with laryngomalacia also have gastro-oesophageal reflux (GOR). The two can amplify each other, reflux irritates the larynx, the larynx becomes more swollen, the noise gets louder. If reflux is significant (frequent visible vomiting, back-arching, fussiness with feeds, weight loss), reflux treatment may help, but reflux itself is also usually self-limiting in healthy babies. See the reflux guide for the full picture.
“Will my baby need an operation?”
Most babies don’t. The procedure for severe laryngomalacia, supraglottoplasty, is reserved for the small minority with significant feeding difficulty, poor weight gain, or breathing pauses. It’s a short day-stay procedure done by a paediatric ENT surgeon: a small trim of the floppy tissue around the airway entrance, usually with an immediate improvement in the sound. Most babies referred for ENT review are seen, observed, and don’t need surgery.
“Is it linked to other problems?”
A small number of babies with laryngomalacia have an associated airway lesion (e.g. a second area of softening lower in the airway, a vascular ring, or vocal-cord issues). These are uncommon. A flexible nasal endoscopy by an ENT specialist, a short, awake exam that takes about a minute, can confirm the diagnosis and rule out a second cause if there’s any doubt.
“Should I avoid loud noises or singing to my baby?”
No. Talking, singing, and the normal sounds of family life don’t worsen laryngomalacia. Cigarette smoke (or being around someone smoking) can worsen any infant airway and should be avoided.
“Will it affect their voice or speech?”
In children whose laryngomalacia resolves naturally, voice and speech are completely normal. After supraglottoplasty, voice and speech are also typically normal, the cords themselves are not involved.
When ENT review is needed
Refer for paediatric ENT (otolaryngology) review when any of the following are present:
- Failure to thrive: slow weight gain or weight loss across the growth chart
- Feeding difficulty: feeds taking >30 minutes, baby tires before finishing, frequent choking, milk coming back through the nose
- Significant breathing pauses: apnoeic episodes >20 seconds, especially with colour change
- Severe work of breathing: chest indrawing, head bobbing or nostril flaring with each breath (not just when upset)
- Recurrent chest infections: three or more in the first year
- Persistent stridor beyond 18 months of age
- A second airway concern: hoarse cry, weak cry, or any sense that the breathing isn’t typical for laryngomalacia
The flexible nasal endoscopy ENT specialists do is short, awake, and well-tolerated by most babies, it doesn’t require sedation. The ENT review confirms the diagnosis, checks for a second airway lesion, and decides whether surgery is needed.
What about feeds?
Most babies with laryngomalacia feed comfortably with no special technique. For the more affected babies:
- Smaller, more frequent feeds can be gentler on a tired infant
- Pacing during a bottle feed (brief breaks, holding the bottle horizontally) gives the baby a chance to coordinate breathing and swallowing
- Feeding upright or semi-upright (rather than reclined) reduces the inspiratory effort
- Burping more often during the feed reduces reflux burden
- Coughs and gags at the end of a feed are very common, usually not serious, but a feeding-team review is sensible if they’re frequent
If feeding is a daily struggle, a paediatric speech pathologist or feeding clinic referral is part of standard care, your paediatrician can arrange this.
Sources beyond this site
For more detail, the Australian-first references at the top of this page are:
- RCH Stridor clinical practice guideline: the same document the on-call team refers to
- RCH Kids Health Info — Noisy breathing: the parent-facing version
Concerned about your baby's breathing?
Not sure if the sound is laryngomalacia or something more urgent? Call (03) 9007 2099 (Mon-Fri 9-5) or your GP. For anything on the red-flag list above, go straight to emergency or call 000.