Flat Spots on a Baby's Head: Prevention and Care

You run your hand over your baby's head and notice that one side, or the whole back, feels flatter than it used to. This is very common in the first months of life, and it is usually something you can help at home. A baby's skull is soft and still growing, so it takes on the shape of whatever it rests against most. The good news is that the same softness that lets a flat spot form also lets it round out again with a few simple changes.

What causes a flat spot

Doctors call this positional plagiocephaly when one side is flat, and positional brachycephaly when the whole back of the head is flat and wide. Both come from steady pressure on the same part of the head. Common reasons include:

• Sleeping on the back with the head turned the same way every night
• Long stretches in car seats, swings, bouncers and carriers, where the back of the head presses against a firm surface
• Little time spent on the tummy while awake
• Tight neck muscles that make it hard for the baby to turn the head both ways
• Crowding in the womb, which is more likely with twins or a large baby
• Being born early, since a premature baby's skull is even softer

A positional flat spot does not affect how your baby's brain grows or works. It is a change in head shape, not a sign of brain damage.

Keep putting your baby on the back to sleep

Some parents worry that back sleeping caused the flat spot and wonder if they should switch. Please don't. Placing your baby on the back for every sleep, naps and nighttime, is one of the most important ways to lower the risk of sudden infant death. The answer is not to change sleep position but to give the head a break from pressure during the hours your baby is awake.

Avoid head-shaping pillows, wedges and positioners. The FDA has warned that these products have not been shown to work and can raise the risk of suffocation. A safe crib has only a firm flat mattress and a fitted sheet.

Tummy time, a little at a time

Tummy time takes pressure off the back of the head and builds the neck, shoulder and arm strength your baby needs to roll, sit and crawl. Start in the first days at home with short sessions of a minute or two, a few times a day, while your baby is awake and you are watching. Slowly add more. The American Academy of Pediatrics suggests working up to about 15 to 30 minutes in total each day by around 7 weeks, and more as your baby gets stronger.

Many babies fuss on their tummy at first. These ideas can help:

• Lie on the floor face to face and talk or sing
• Lay your baby on your chest while you recline
• Place a toy or an unbreakable baby mirror just in front of them
• Try tummy time after a diaper change, when your baby is alert but not hungry
• Stop when your baby gets tired, and try again later

Read more on the AAP parent site about back to sleep and tummy to play.

Simple repositioning tricks

Babies like to look toward the room, the door, or you. You can use that to encourage them to turn the head the other way:

• Switch which end of the crib your baby's head goes at each night, so the interesting view is on the other side
• Switch the arm you hold your baby in during feedings, for bottle and breast alike
• Change where you stand when you talk to your baby on the changing table
• Carry your baby upright in your arms or a carrier instead of moving them from seat to seat
• Take your baby out of the car seat once you arrive, rather than leaving them in it to nap

Tight neck muscles (torticollis)

Some babies have a tight muscle on one side of the neck. This is called torticollis. You might notice that your baby always tilts the head to one side, turns to look only one way, or gets upset when you try to turn the head gently. Because the head rests in the same spot over and over, torticollis and flat spots often show up together.

If your pediatrician finds torticollis, they may refer you to a physical therapist. The therapist can teach you gentle stretches and positioning to do at home. Starting early tends to work best, so mention a head tilt at your baby's next visit or sooner.

When are helmets considered?

Most flat spots get better on their own as babies spend less time lying down, start rolling and learn to sit up. Repositioning and tummy time are the first steps for nearly every baby.

For a moderate or severe flat spot that has not improved with these steps by about 5 or 6 months of age, your pediatrician may talk with you about a custom-fitted helmet. A specialist makes and adjusts the helmet, which gently guides the growing skull into a rounder shape. A helmet works best while the head is still growing quickly, which is why timing matters. It is not needed for most babies.

Not every odd head shape is positional

Rarely, an unusual head shape comes from a condition called craniosynostosis, where one or more of the seams between the skull bones close too early. This needs a specialist and sometimes surgery. Your pediatrician checks for it by feeling your baby's head and looking at its shape from above. That is one reason to point out any head shape you are unsure about rather than waiting. The AAP has a helpful overview of positional skull deformities and torticollis.

When to call us

Call your A thru Z Pediatrics office if:

• A flat spot is getting worse, or is not better after a few weeks of repositioning
• Your baby always tilts the head or turns only one way
• You see a ridge along the skull, or the soft spot on top seems to have closed early
• One ear, eye or cheek looks pushed forward compared with the other side
• Your baby is not lifting the head during tummy time by the age you expect

A flat spot by itself is not an emergency. Call 911 or go to the ER if your baby has a head injury and becomes very sleepy, vomits again and again, has a seizure, or the soft spot is bulging.

Have a question about your baby's head shape? You can request a visit.