Updated: Jun 11
It's natural to feel worried if you notice that your infant's head is asymmetrical—after all, you want them to be perfect! But not to worry—this is a common occurrence, is almost always harmless, and usually corrects itself as your baby gets older.
This article will discuss the causes of a flat head, ways to reduce the likelihood of one developing, and the remedies available if your baby does have a flat spot.
In this article:
What is flat head syndrome?
Many babies develop an asymmetrical head shape or flattened spot on the side or back of the head after birth. This is often called "flat head syndrome."
You are far from alone if your baby develops a flat spot.
A 2013 study found that approximately 47% of infants have some degree of flat spot and the vast majority are mild cases.
This breaks down to:
Flat head syndrome does not impact the baby's brain development or intelligence. It is almost entirely a cosmetic issue.
Types of flat head syndrome
There are two main types of asymmetry that a baby's skull can develop.
Plagiocephaly is the medical term for a baby's head that has a flat spot on one side and looks asymmetrical. In some cases the ears may become misaligned and the forehead and/or cheek may shift forward on the flattened side.
This is the most common type of flat spot.
Brachycephaly is when the back of the baby's head flattens, causing the entire head to become wider. Sometimes this can cause the forehead to bulge, but generally brachycephaly has less of an impact on a baby's facial features.
This diagram shows the impact of plagiocephaly and brachycephaly on a baby's skull, as seen from above.
For the purposes of this article, we will discuss both types together as "flat head syndrome."
Causes of a flattened head
There are several causes of flat head syndrome:
1. Head position after birth
Positional plagiocephaly (sometimes referred to as "deformational plagiocephaly") or brachycephaly occurs when babies lie with their heads in the same position for a long time, putting constant pressure on the back or side of their skull. Because babies' bones are more flexible, too much pressure on one area can create a flat spot.
The reason for this is that a baby’s head grows where there is open space. If a child is always laying on their back and looking to the left, there is no room for the head to grow there and it will become flat. Instead, the head will grow on the front and right side, causing facial features to shift as the head grows larger.
Positional plagiocephaly or brachycephaly often occurs if a baby spends too much time lying on their back in baby swings, carriers, or car seats.
Just remember that it's essential for you to continue to put your baby on their back for sleep, even if it results in a flat spot. Tummy sleeping is a major cause of sudden infant death syndrome (SIDS).
2. Position in the womb
If there is pressure on a baby's skull in the womb or there isn't enough amniotic fluid to cushion their head, they can even develop a flat spot before birth. This is more common with multiples (twins, etc.), who have less space in the womb.
3. Congenital muscular torticollis
Congenital muscular torticollis is a condition seen in newborns where the muscle that runs down the side of their neck is shortened and tight. As a result of their tight neck muscles, babies may tilt their heads to one side and have trouble turning their heads to the opposite side.
This could be caused by a baby's position in the womb or by an injury to the neck muscle before birth.
Because babies with torticollis have limited neck mobility and a strong preference for turning their heads to one side, they can develop a flat spot as a result of keeping their head in one position.
4. Premature birth
Premature babies are more likely to develop a flat spot on their head. Their skulls tend to be softer after birth, making them more easily molded. A premature baby may also be less able to move their own head, causing them to keep their head in the same position.
When to contact your child's doctor
Any time you have any concerns about your baby's head shape, it's worth mentioning it to their doctor. A doctor can diagnose flat head syndrome, provide advice on ways to correct it at home, and provide referrals for physical therapy or helmet therapy, if necessary.
We'll discuss these treatments in more detail below.
Your child's doctor will also likely be checking and monitoring their head shape at their well child visits.
How to treat flat head syndrome
If your baby's head shape is uneven, don't worry!
Mild cases of flattened heads often don't require any treatment.
As your baby moves around more and naturally spends more time in different positions, their head shape will often correct itself as they grow.
And even if your baby does need treatment, there are many remedies and therapies that can correct their head shape, many of which you can do with your baby at home.
If you're concerned about your baby's head shape, talk with your baby's health care provider. But ultimately, remember that most people don't have perfectly round heads—don't agonize over every small bump!
1. At-home remedies
Changes in the way you position your baby can help correct unevenness in their skull. When a baby is positioned in various positions throughout the day, all parts of their head have an opportunity to be in open space, and can grow more evenly.
Your healthcare provider may suggest that you do the following:
1. Change your baby's sleep position.
They should always sleep on their back, but you can alternate your baby's head position in the crib.
For example, if your baby always turns their face towards the window, place them with their head at the "foot" of their crib so they have to turn the other way to face the window. Alternate ends of the crib each night.
Or try hanging a mobile over the crib to encourage your baby to move their head.
2. Alternate sides for feeding.
Similarly, if you bottle feed your baby, try alternating the arm that you hold them with for each feeding so that their head is not always facing the same direction while they eat.
If you breastfeed, you are most likely already alternating sides during a feeding.
3. Hold your baby frequently.
Hold your baby upright as much as possible while they are awake, in your arms or a baby carrier, to reduce the pressure on their head.
4. Maximize tummy time.
Place your baby on their tummy to play as often as possible when they are awake. Be sure to use a firm surface for tummy time and supervise your baby closely.
2. Physical therapy
When an underlying muscular issue, such as torticollis, causes a baby to hold their head tilted to one side, physical therapy is usually necessary.
Physical therapy can help stretch and strengthen the affected neck and head muscles so that the baby can change their head position more easily and reduce pressure on one spot.
Physical therapy can also help your baby achieve milestones that may become difficult or delayed due to head rotation preference.
3. Helmet therapy
If the at-home changes and physical therapy don't work or if the head asymmetry is severe, your pediatrician might prescribe helmet therapy with a molding helmet (also called a cranial helmet or cranial orthosis). A molding helmet is designed to relieve pressure on the flat side of your baby's head and is custom fit to each child.
Babies generally wear a molding helmet for 23 hours per day, with a break for bath time.
Most babies quickly become accustomed to wearing a helmet and do not experience any discomfort. If your baby does seem uncomfortable, their helmet may need to be adjusted.
Helmet therapy is most effective between the ages of 4 and 12 months, when your baby's skull bones are most flexible and their brain is still growing rapidly.
After age 1, head growth slows down and the skull plates fuse together, so helmet therapy becomes less successful.
Helmet therapy will generally be the most effective and take the least time if it begins as early as possible. A baby will usually need to wear a helmet for several months, and in some cases may need a second helmet.
Above all, don’t worry if your doctor recommends a helmet for your baby. This treatment is fairly common and will not hurt your baby. They'll be done with their cute headgear before you know it!
4. WARNING: Baby flat head pillows are not safe
You may have seen “flat head pillows” advertised that claim to treat or prevent flat spots. Infant head shaping pillows are not FDA-approved and are dangerous for babies.
You should never put any soft or loose object in your baby’s crib because these items can increase the risk of sudden infant death syndrome (SIDS) and suffocation.
Moreover, these products do not actually prevent or correct flat heads. A far more effective approach is to vary your baby’s head position without using any device and make sure they have plenty of supervised tummy time.
Preventing flat head syndrome
You can reduce the likelihood that your baby will develop a flat spot by following the tips above for varying your baby's head position. Specifically, keep the following guidance in mind:
1. Let your baby move!
When possible, limit the time that your baby spends in car seats, infant carriers, and bouncers. These items restrain your baby's head movement and keep them in one position, putting pressure on one spot of their skull. The World Health Organization recommends that babies not be restrained for more than an hour at a time.
For car seats in particular, the recommendation is that babies under 4 weeks should spend no more than 30 minutes at a time in a car seat.
This guidance is specifically concerned with strain on a baby's spine and restricted airflow to their lungs, but also helps to avoid flat spots.
Even after 4 weeks, babies should spend no more than 2 hours at a time in a car seat.
Instead, your baby should spend plenty of time on the floor engaging in play and interacting with caregivers.
2. Encourage tummy time
Your baby should have at least 30 minutes of supervised tummy time over the course of the day.
Plenty of tummy time not only prevents flat spots, but also strengthens your baby's neck and core and helps them prepare for crawling.
If you'd like ideas for how to keep your baby happy and entertained during tummy time, check out the Pathfinder Health app for tummy time guidance and activities.
Other causes of an abnormal head shape
There are numerous other conditions that can cause an abnormality in head shape or size. Some of these—such as craniosynostosis, macrocephaly (abnormally large head size), and microcephaly (abnormally small head size)—are rare but serious conditions.
Far more common is a misshapen head as a result of the birth process itself. Three common ways that birth can impact a baby's head shape are cone head, caput succedaneum, and head molding from birth-assisting tools.
1. Cone head
Sometimes a newborn's head is molded unevenly due to the tight squeeze of passing through the birth canal. This can result in an uneven head shape. To immediately dispel one myth, it is completely normal for babies to be born with unevenly shaped heads—even cone-shaped heads—as a result of the birth process.
A cone-shaped head is particularly likely to occur if a baby drops into the mother's pelvis early or if the mother has a narrow birth canal and/or a long labor.
A baby's conehead appearance after birth usually resolves on its own. Often, the head will regain its round shape after the first few days, although it may take other babies a few weeks to lose the cone shape entirely.
2. Caput succedaneum
Caput succedaneum is another potential side effect of birth on a baby's head. It refers to swelling, puffiness, and possible bruising of a baby's scalp as a result of vaginal birth.
Caput succedaneum is most often caused by pressure from the uterus or vaginal wall during a head-first delivery, especially a long or hard delivery.
Just like a cone-shaped head, caput succedaneum goes away on its own, usually within a few days after birth.
3. Birth-assisting tools
Use of forceps or a vacuum during birth can also impact a baby’s head shape. Forceps can cause a slightly pinched appearance on the sides of the head. A vacuum can cause a lump on the top of a baby’s head.
Most instances of head molding caused by forceps or a vacuum will resolve themselves with time or changes to a baby’s position. However, you should always consult with your doctor if you have any concerns.
Frequently Asked Questions
1. Does a baby's flat head correct itself?
Mild cases of flat head syndrome often correct themselves. As a baby strengthens their neck muscles and learns to roll over, they spend less time in one position and put less pressure on one spot of their skull. Their head will continue growing into a rounder shape.
2. How is flat head syndrome treated?
Milder cases can be treated by varying a baby’s head position, through changing their sleeping position, encouraging plenty of tummy time, and increasing time spent upright. More serious cases may require a molding helmet to relieve pressure on the flat side and encourage growth.
3. Are flat head pillows safe for babies?
No, it is never safe to put any kind of pillow in a baby’s crib. Any soft or loose object in a baby’s crib increases the risk of sudden infant death syndrome (SIDS) and suffocation.
4. Do pillows help with a baby’s flat head?
Pillows do not help correct a flat head, which is better treated by varying head position without use of any device. Putting any kind of pillow in a baby’s crib is dangerous and increases the risk of sudden infant death syndrome (SIDS) and suffocation.
5. When is it too late to correct a flat head?
Helmet therapy and other strategies for correcting head shape become less effective after one year. Head growth slows down after this age. Moreover, the gaps between babies’ skull plates begin to close, making their heads less moldable.
6. Can a flat head be corrected after 6 months?
Yes, at 6 months a baby’s skull is still growing rapidly and is still moldable, so flat spots can still be corrected. However, treatment will be more effective and take less time if it begins as early as possible, so don’t delay!
It's fairly common for babies to develop an uneven head shape from spending too much time in one position. Don't worry—this doesn't mean that something is wrong with your little one. Often your baby's head will correct itself on its own. There are also many steps you can take to help your baby's head regain its rounder shape.
If you need more reassurance, reach out to a medical professional who will be able to help you further understand how best to get that precious head back into form!
Mawji A, Vollman AR, Hatfield J, et al. The Incidence of Positional Plagiocephaly: A Cohort Study. Pediatrics (2013) 132 (2): 298–304. https://doi.org/10.1542/peds.2012-3438
Ita MI, Weisbrod LJ, Rizvi MB. Brachycephaly. [Updated 2022 Nov 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK567709/