You may have noticed a very specific accessory on many of the babies you see at daycare drop off, strolling through the park, or peppering your social feeds…and no, it’s not tiny Vans or trendy baby turbans. More and more babies today are wearing what’s dubbed cranial molding helmets to help fix flat head syndrome. But do baby helmets work for flat head? And why do so many infants have flat spots on their heads anyway? Here, learn all about flat head prevention and the treatments that actually work.

What is flat head syndrome?

Plagiocephaly is most often referred to as flat head syndrome…and for good reason. Flat head syndrome is marked by a flat spot on one side—or the back—of a baby’s head. It usually comes about because your little one favors snoozing with their head turned to the same side, sleep after sleep. But parents can breathe easy knowing that for the most part, positional skull deformities, like flat head syndrome, don’t affect brain growth or intellectual development.

How common is flat head syndrome?

Approximately one out of four babies who sleep on their back develop flat head syndrome. After the American Academy of Pediatrics (AAP) began to officially recommend that all infants sleep on their backs in the early 1990s, the incidence of flat head syndrome increased by approximately 600%, and it keeps going up every year. (It’s important to note that incidences of SIDS decreased by more than 40% with this safe-sleep rule.) Flat head syndrome is most likely to occur during Baby’s first four to 12 weeks of life.

What Causes Flat Head Syndrome in Babies

An infant’s skull is soft and malleable so that their brain has room to grow and their head can pass safely through the birth canal. (If your little one was born with a bit of a cone head, you know what we’re talking about!) But having a soft skull can lead to flat head syndrome. Here are the main causes of flat head syndrome:

  • Regularly laying in one position: It’s not just a crib or bassinet mattress that can place consistent pressure on the same spot on your baby’s head. Being in an infant car seat, a baby carrier, stroller, swing, or bouncy seat for long stretches can also lead to flat head syndrome.

  • Position in the womb: When babies grow in a small uterus, they’re especially likely to have flat head syndrome. (About 20% of babies are born with a misshapen head due to circumstances in the womb or birth canal.)

  • Prematurity: Because preemie’s skulls are softer than those of full-term babies, they’re more prone to plagiocephaly. Plus, when any baby, including premature babies, are in the neonatal intensive care unit (NICU), they spend lots of time on their backs.

  • Torticollis: Here, little ones have tight or shortened neck muscles that cause their head to tilt to one side. About 85% of babies with torticollis have a positional skull deformity.

  • Not enough tummy time: According to the AAP skimping on supervised, regular tummy time interferes with Baby mastering the task of lifting their head.

  •  Congenital condition: In rare cases, flat head is caused by a congenital condition called craniosynostosis, where a baby’s skull bones fuse together before they’re supposed to.

Who’s at risk for flat head syndrome?

In addition to the above causes, experts note that some children are more likely to develop flat head syndrome than others. Some additional risk factors that may elevate a child’s chances of plagiocephaly, include:

Does SNOO cause flat head syndrome?

SNOO is no more likely to cause flat head syndrome than any other crib or bassinet! That’s because flat head isn’t due to your baby’s sleep space, but their sleep position…specifically, back-sleeping—which is the number one safe-sleep position recommended by all leading children’s health experts. If your infant has a preferred head position while sleeping in SNOO, regularly rotate SNOO to encourage your bub to turn their head in the opposite direction. (Babies naturally turn toward light or high-contrast objects.)

Signs of Flat Head Syndrome

To get a good look at your baby’s head, check their skull shape after bathtime when their hair is wet. The back of your little one’s head should be evenly round, their ears should be even, and the width of your bub’s head and forehead should be balanced. If you’re unsure if your child’s head looks “normal,” refer to this list of signs of flat head syndrome:

  • Bald spot

  • Flat area on the back, side, or front of the head

  • Misshapen or slanted head

  • One cheek looks fuller than the other

  • Uneven ears (one pushed forward or upward)

More serious flat head signs include:

  • Forehead may bulge on the side opposite of flattening

  • No soft spot on Baby’s head

  • Stunted head growth

  • Uneven facial features or other facial defects

  • Ridges or hard edges along skull

When to Call the Doctor for Flat Head

While your child’s healthcare provider will be monitoring your baby’s growth and appearance during their regularly scheduled well-child visits, never hesitate to reach out if you’re concerned.

The pediatrician will examine your bub’s skull and check for both plagiocephaly and the genetic condition, craniosynostosis.

How Flat Head Syndrome in Babies Is Diagnosed

Your child’s pediatrician will examine your little one’s noggin during well-baby visits to determine if their head shape is symmetrical. They’ll be able to diagnose flat head syndrome simply by looking and possibly utilizing a device called a diagonal caliper. This handheld tool simply measures the difference between the diagonal lengths on each side of the head. To check for torticollis, or tight neck muscles, your pediatrician may also watch how easily your baby can move their head and neck. If the doctor suspects craniosynostosis, they will likely perform an X-ray, ultrasound, or MRI.

If your child gets a diagnosis for flat head syndrome, your child’s healthcare provider may refer you to a specialist such as a neurosurgeon or a craniofacial specialist. (Don’t panic! This in no way means your baby needs brain surgery!) If your bub has torticollis, they’ll likely be referred to a physical therapist to boot.

How to Prevent Flat Head Syndrome

The best treatment for flat head syndrome is prevention. But when positional plagiocephaly is spotted early, simple tweaks to your baby’s everyday can help, like…

  • Limit time spent in swings, bouncers, car seats, and strollers.

  • Frequently cuddle with your baby by holding them upright over one shoulder.

  • Place toys on both sides of the car seat and play mat to encourage head movement.

  • Switch arms when holding and feeding your baby.

  • Change up the direction your baby lays in the crib and on the changing table.

  • Regularly rotate their bassinet.

  • Increase tummy time.

Tummy Time and Flat Head Syndrome

When your baby spends time on their tummy (while awake and supervised), it takes pressure off their head, which is needed to help prevent—and treat—flat head syndrome. Research has shown that infants who received tummy time less than three times a day were at greater risk to develop flat head at 7 weeks old. Plus, regular tummy time helps your baby learn to hold their head up and develop the gross motor skills they’ll need to sit, crawl, and walk.

  • For 3 to 5 minutes a few times a day, place your baby on their belly across your chest or lap for some starter tummy time.

  • At around 2 months, take daily tummy time to a playmat on the floor. Do this several times a day, gradually increasing time spent on the belly.

  • Move toys side to side so your little one will move their head to follow them.

  • Make a habit to do tummy time when your bub is happy and relaxed, like after a diaper change or when your baby wakes from a nap.

  • Work up to 20 minutes of tummy time a day by the time your little one is 3 to 4 months old. (This can be split into multiple sessions.)

Do head-shaping pillows prevent flat head?

No…and they’re dangerous! The Food and Drug Administration (FDA) could not be more clear: Infant head shaping pillows to prevent or treat flat head syndrome—or any medical condition—offer no benefit and are unsafe. Remember, when an infant sleeps with a pillow of any kind, it contributes to their overall risk of suffocation and death. A safe crib or bassinet is one that’s 100% free of all loose bedding, including pillow, blankets, and crib bumpers. (Learn more sleepytime products to keep out of your baby's crib.)

Flat Head Syndrome Treatments

In addition to using the above preventative strategies as treatment, here’s an age-by-age guide on how to treat flat head syndrome, according to a 2020 report in the Archives of Craniofacial Surgery:

Up to 4 Months:

  • Posture change
  • Physical therapy including neck exercises (especially for torticollis)

4 to 6 Months:          

  • Posture change (mild to moderate plagiocephaly)
  • Helmet therapy (severe plagiocephaly)

6 Months+:                

  • Helmet therapy

Helmets for Baby Flat Head Syndrome

Conservative treatments, like supervised tummy time, physical therapy, and regularly changing your baby’s position, are first-line treatments for flat head syndrome. If after giving those treatments a solid try (as determined by your baby’s healthcare team), your bub’s head still features a prominent flat spot, helmet therapy may be an option. Helmet therapy for flat head syndrome consists of wearing a custom corrective helmet around 20 hours a day for two to six months. The constructive nature of a helmet helps promote proper growth of your baby’s skull. (Don’t worry, it’s painless.)

The big question, of course, is: Should I get a helmet for my baby’s flat head? The answer is… maybe. A 2014 study in BMJ looked at 84 babies who had moderate to severe flat head syndrome. Starting at 6 months old, half wore a custom helmet for 23 hours a day over six months, the rest got no treatment. By the time all the babies were 2 years old, researchers determined that there was no significant difference between the babies’ head shapes. But that doesn’t necessarily mean a helmet won’t help your child’s flat head.

The National Association for Plagiocephaly reports that helmets for flat head syndrome are most effective for babies 4 to 8 months old. And the AAP notes that babies who start helmet therapy at a younger age may wear the helmet for less time and may experience better results. Regardless, it’s important to know that helmet therapy is always a choice (not mandatory) and while helpful to some, not every baby with a flat head needs a helmet. According to experts, head shape often gets better with or without the use of a helmet. Of course, discuss all your options with your baby’s healthcare team.

More Newborn Must-Reads




  • The Nemours Foundation, KidsHealth: Flat Head Syndrome (Positional Plagiocephaly)
  • American Academy of Pediatrics (AAP): When a Baby’s Head is Misshapen: Positional Skull Deformities
  • UCLA Health: Does your baby need helmet therapy? 5 facts about flat head syndrome
  • Diagnosis and treatment of positional plagiocephaly. Archives of Craniofacial Surgery. April 2020
  • Stanford Medicine Children's Hospital: Flat Head Syndrome (Deformational Plagiocephaly)
  • Torticollis in Infants with a History of Neonatal Abstinence Syndrome. The Journal of Pediatrics. January 2018
  • Massachusetts General Hospital: Head Shape Differences in Infants: What You Need to Know
  • Delayed Motor Development and Infant Obesity as Risk Factors for Severe Deformational Plagiocephaly: A Matched Case–Control Study. Frontiers in Pediatrics. November 2020
  • American Academy of Family Physicians: Plagiocephaly
  • American Association of Neurological Surgeons: Positional Plagiocephaly
  • Risk factors for deformational plagiocephaly at birth and at 7 weeks of age: a prospective cohort study. February 2007
  • Tummy Time and Infant Health Outcomes: A Systematic Review. June 2020
  • AAP: Back to Sleep, Tummy to Play
  • S. Food and Drug Administration (FDA): Do Not Use Infant Head Shaping Pillows to Prevent or Treat Any Medical Condition: FDA Safety Communication
  • JUNE 21 2022
  • Sleep-Related Infant Deaths: Updated 2022 Recommendations for Reducing Infant Deaths in the Sleep Environment. June 2022
  • The National Association for Plagiocephaly: Treatments for Plagiocephaly
  • Helmet therapy in infants with positional skull deformation: randomised controlled trial. BMJ. May 2014
  • AAP: Baby Helmet Therapy: Parent FAQs
  • Children’s Hospital of Orange County: Infant head shape problems and helmet therapy: What parents should know

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.