What Is Flat Head Syndrome (Plagiocephaly Or Brachycephaly)?

Learn what flat head syndrome is, the two different types, whether it's a cause for concern, and how to remedy it. We'll also share tips prevent flat head syndrome while still keeping baby safe during sleep.

What is flat head syndrome, and what's the difference between the two different types of this condition (plagiocephaly and brachycephaly)? Is baby's flat head a cause for concern? And when to see a doctor about flat head syndrome?

We'll answer all these questions and more in this parents' guide.

What is flat head syndrome?

Flat head syndrome is a very common condition that affects the shape of baby's head. It causes flat spots on the side or back of baby's head.

Some sources, including the UK's National Health Service, estimate that as many as one in five babies develop flat head syndrome. Other sources, including the American Academy of Family Physicians, estimate that the number is as high as 50% of babies.

There are two main types of flat head syndrome:

  • Plagiocephaly, where one side of baby's head has a flat spot and baby's head looks asymmetrical (differently-shaped on each side)
  • Brachycephaly, where the back of baby's head is flat and baby's head looks widened

Flat head syndrome is most common in babies ages 6 weeks to 2 months of age.

What does flat head syndrome look like?

Signs of flat head syndrome include:

  • A flat spot on the side or back of the head
  • A head that looks slanted rather than round
  • Uneven-looking ears
  • A bald spot on the flatter area of the head
  • Hard ridges on the head
  • No soft spot (fontanel) on the head

The best time to look for signs of flat head syndrome is after baby's bath, because their wet hair makes their head shape more visible.

What causes flat head syndrome?

Flat head syndrome happens because a newborn baby's skull is made up of soft plates that can easily shift. The softness of these plates gives baby's quickly developing brain -- and other parts of their head -- plenty of room to grow.

Baby's skull plates won't join together completely, and won't harden, until later in baby's first year of life.

This means baby's head could easily change shape, or flatten, when pressure is placed on one area of the head.

Sometimes, flat head syndrome happens when baby passes through the birth canal, and that pressure on the skull plates flattens the side or back of baby's head.

Other times, pressure is placed on baby's head in the womb, causing it to flatten.

And babies born prematurely may be more prone to flat head syndrome, as their skull plates are even softer than the skull plates of full-term babies.

But most commonly, flat head syndrome happens when baby stays in the same position for long periods of time, such as often lying on their back.

Should you be concerned about flat head syndrome?

Flat head syndrome is usually not a cause for concern. It isn't painful for baby, and it doesn't affect their development (including their brain development).

Plus, baby's head shape will usually "correct" itself over time, most often within a few months, as baby varies the position of their head more. Flat head syndrome will usually resolve completely by 1-2 years of age.

Remember -- even though flat head syndrome often results from baby spending a lot of time on their back, it's crucial to always put them to sleep on their back.

Sleeping on the back sharply reduces their risk of sudden infant death syndrome (SIDS). Keeping baby safe during sleep is most important!

The number of babies with flat head spots has grown, but that's surprisingly a good sign. It indicates that more parents are using the safe sleep practice of putting baby to sleep on their back. And most of these cases of flat head syndrome are mild, and resolve on their own.

Dr. Lewis First of UVM Children's Hospital shares more about why you shouldn't worry about flat head syndrome with WPTZ-5 News:

When to see a doctor about flat head syndrome?

If you suspect flat head syndrome, you should talk to your doctor as soon as possible.

This is important, because your doctor needs to make sure that baby has flat head syndrome and not the more serious craniosynostosis. (Craniosynostosis results when baby's skull plates fuse together too early, causing a flatter head shape that's extremely difficult to change.)

If it is flat head syndrome, your doctor will determine if the case is mild or more serious. Rest assured, though, that the vast majority of cases are mild.

Your doctor will give you guidance on how to reduce the pressure on baby's head and correct the "flattening."

How to treat -- or prevent -- flat head syndrome?

In most cases, you can reduce the pressure on baby's flat head spots by taking steps at home.

  • Give baby "tummy time" multiple times per day, while they are awake and ready for playtime.
    • This encourages baby to develop neck and shoulder muscles, and lift their head.
    • Eventually, it will help them develop the motor skills needed to sit up, roll over, crawl, and even walk.
    • It also relieves the pressure on the back of baby's head. This can help stop plagiocephaly or brachycephaly from developing in the first place.
    • And it can help reverse flat head syndrome in babies who already have it.
      • 30 minutes of tummy time per day is recommended for babies who already have plagiocephaly or brachycephaly.
  • Carry baby often, either in your arms or in a sling carrier.
    • Carry them when you can while they are awake, instead of keeping them in the crib or a stroller
    • Take them out of their carseat and carry them when at your destination.
  • Change the sides and positions you use when feeding and carrying baby.
  • While baby is awake, reduce the time they are lying on their back by as much as you can.
    • Vary the positioning of their head throughout the day.
    • But always continue to put baby to sleep on their back, as this is the safest sleeping position!
  • When baby goes down to sleep, turn their head slightly to one side while keeping them on their back.
    • In most cases, you should switch the side you turn the head to each time. If you turned it to the left last time, turn it to the right this time.
    • If baby has a flat spot on one side of the head, turn baby's head the opposite way.

What if baby's flat head shape still doesn't improve?

Usually, taking the above steps will help baby's flat head syndrome resolve.

If baby's flat head syndrome doesn't improve by around age four months, talk to your doctor again. They may recommend helmet orthosis, a type of therapy where baby wears a helmet. The helmet used in this therapy is designed to encourage baby's skull plates to grow into a round shape, and keep their head from flattening out further (even when pressure is placed on a flat spot).

(For more information on helmet orthosis, please read this article from the American Academy of Pediatrics.)

Key takeaways for parents

Remember that flat head syndrome very rarely causes harm to your baby. It usually only affects their appearance.

Varying baby's head position throughout the day, while they are awake, is the best way to prevent or remedy flat head syndrome. Give baby tummy time during play -- it has the added benefit of building baby's muscles.

But remember -- keeping baby safe during sleep is most important. Always put baby to sleep on their back, to reduce their risk of sudden infant death syndrome (SIDS). "Back to sleep" is safest!

If you think your baby has flat head syndrome, you'll want to talk to your doctor. They'll give you an official diagnosis.

Especially with the right steps, and with your doctor's guidance, flat head syndrome will usually go away on its own.

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