How to prevent flat head syndrome

How to prevent flat head syndrome
Flat head syndrome: How to make sure your baby develops a round skull.

Flat head syndrome is typically only a cosmetic problem. It won’t compromise your child’s brain growth or development. That said, it’s important to take certain steps to ensure your baby’s skull doesn’t become flat.

What causes flat head syndrome?

At birth, babies’ skulls are soft and malleable. This is what makes it possible for the head to pass through the vagina during delivery. As a result, it’s not uncommon for a newborn’s head to be slightly misshapen. Things typically resolve themselves in the first few weeks after birth.

However, some neonatal syndromes can worsen, and others may arise in the first few months after the baby is born. A flat skull usually starts to be apparent around 2 months of age.

From the time they are born, it’s important to change the way you support your baby’s head, since the weight of a newborn’s head is relatively heavy compared to the rest of their body. Because their neck muscles are weak, their head will tilt to one side or the other while they sleep. If a baby always sleeps in the same position, the bone located behind their ear will gradually flatten. Cases of flat head syndrome have become more frequent, since experts typically recommended that infants should sleep on their backs to prevent sudden infant death syndrome.

The larger the child’s head, the less their muscles are able to support it, increasing the risk of flat head syndrome. Also at greater risk are premature babies, babies with developmental disorders, and boys (because they have less muscle tone than girls at the same age).

In most cases, flat head syndrome only occurs on one side of the head. But sometimes the entire back of the head can become flat, creating the illusion that the back of the neck extends all the way to the top of the head.

The risk of developing flat head syndrome is greater when a baby stays in the same position for a long time. This can happen when the baby is often placed in a seat with a hard surface (such as a stroller, the car, the seat in the grocery cart, etc.). If they are left in their seat for too long without moving, the unique position they are in could change the shape their skull.

At birth
Some babies have a flat head when they’re born because of the way their skull took shape in the uterus (e.g., if they dropped into the pelvis earlier in the pregnancy or if they experienced space constraints due to the presence of a twin). Any visible defect at birth should quickly be evaluated by a physician to rule out causes other than the moulding of the skull, including premature closure of the skull sutures.

How can you prevent your baby from developing a flat head?

  • From the time they’re born, make sure your baby’s head isn’t always resting on the same side when you place them in their crib.
  • As soon as they’re able to turn their head on their own, make sure it’s not always turned to the same side. To achieve this, alternate the position in which you put them to bed—with their head at the foot of the bed one night, and on the other side the next. A source of noise or visual cue such as a mobile, will attract their attention and encourage them to naturally turn their head to the other side.
When they’re awake, make sure to you hold your child in different positions, letting their head be free and not under constant pressure.
  • If you are bottle-feeding your baby, alternate the arm you use to support their head during feedings. This will ensure you’re not always supporting the same side of your baby’s head with your elbow.
  • Place your baby on their stomach every day. To encourage them, you can lie down while facing them or put a toy in front of them. The Canadian Paediatric Society recommends that babies should be placed on their stomachs every day for at least three periods of 10 to 15 minutes each.
  • Limit the amount of time your baby spends with their head resting on a hard surface, such as the floor or in a swing. Their car seat should only be used when they are in the car.
  • Encourage your baby to look in both directions by showing them a toy first on their right side, and then on their left.
  • Have fun lying on your back “tummy-to-tummy” with your baby. Always keep your hands on them to prevent them from falling.
  • Carry your child in a soft baby carrier against you, as this can decrease the risk of developing a flat head.

How do you correct a flat head?

It’s important to consult your doctor if you notice that your baby has a flat head. If treated early enough, ideally before the age of 4 months, the condition tends to disappear in the vast majority of cases. A misshapen skull can also be the result of other causes, such as torticollis or the premature closure of a suture. This requires other types of treatment.

Even if your baby’s flat head doesn’t resolve itself completely, it will be hardly noticeable in adulthood.

Generally, regularly changing your baby’s sleeping position is enough to restore the shape of their skull within a few months. Physiotherapy exercises may also be recommended to help promote the head’s range of motion.

In rare cases, moulding helmets can help the head regain its shape. These are most useful if the flat head has not improved by the age of 4 months despite repositioning and physiotherapy. They are less effective after 6 months of age. A few studies published in recent years question whether they are useful in cases of moderate to severe asymmetry.

Skull formation: a process that lasts until the age of 2
At birth, the skull is made up of 6 bones that are not yet fused. They are linked together by sutures and by empty spaces called fontanelles. The easiest to spot is the anterior fontanelle, which is the soft spot located just above the head. It begins to close around 9 months of age. It’s normal for the fontanelle to move as your baby breathes and rise when they cry, especially when they are lying down.
The bones of the skull gradually expand as the brain grows. In time, each bone falls into place and fuses to the neighbouring bones, filling in all the gaps. Around the age of 2 years, the skull will almost consist of a single piece.

When should you consult a doctor?

It’s important to consult a doctor if you notice that your baby:

  • Seems to have a flat head.
  • Has limited neck movement, as this could be a sign of torticollis.
  • Experiences any delay in their motor development.
  • Experiences continuous bulging of the fontanelle while sitting, or if the fontanelle is not yet closing after the age of 24 months.

Things to keep in mind

  • Flat head syndrome usually starts to be apparent around 2 months of age.
  • To prevent a flat skull, from the moment they are born, make sure your baby’s head isn’t always resting on the same side.
  • If you notice that your baby has a flat head, schedule an appointment with your pediatrician.


Naître et grandir

Scientific review: Dr. Anne-Claude Bernard-Bonnin, pediatrician
Research and writing: The Naître et grandir team
Updated: February 2020




Sources and references

Note: The links to other websites are not updated regularly, and some URLs may have changed since publication. If a link is no longer valid, please use search engines to find the relevant information.

  • Di Chiara, Anna, et al. “Treatment of Deformational Plagiocephaly with Physiotherapy.” Journal of Craniofacial Surgery, vol. 30, no. 7, October 2019, pp. 2008-2013.
  • Doré, Nicole, and Danielle Le Hénaff. From Tiny Tot to Toddler: A practical guide for parents from pregnancy to age two. Institut national de santé publique du Québec, Quebec City.
  • Kutlu, Nadielle. “Encore trop de bébés à la tête plate.” La Presse, October 24, 2017
  • Lennartsson, Freda, et al. “Teaching Parents How to Prevent Acquired Cranial Asymmetry in Infants.” Journal of Pediatric Nursing, vol. 31, no. 4, July-August 2016, pp. e252-e261.
  • Linz, Christian, et al. “Positional Skull Deformities.” Deutsches Ärzteblatt International, vol. 114, no. 31-32, August 2017, pp. 535-542.
  • Ordre professionnel de la physiothérapie du Québec. “Plagiocéphalie : pourquoi mon bébé a-t-il la tête plate?”
  • Canadian Paediatric Society. Caring for Kids. “Preventing flat heads in babies who sleep on their backs.” 2016.
  • Canadian Paediatric Society. “Positional plagiocephaly.” 2011.

    Lien périmé en français. Nous avons donc remplacé le lien avec ce qui semble être le bon en anglais:

  • Van Wijk, Renske M., et al. “Helmet therapy in infants with positional skull deformity: randomised controlled trial.” British Medical Journal, vol. 348, May 2014.