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Baby's head shape: What's normal?

Medically reviewed on Mar 13, 2018

Many newborns have slightly uneven heads. But is it cause for worry? Understand what causes unevenness in babies' heads and when treatment is needed.

What causes a baby's head shape to appear uneven?

Sometimes a baby's head is molded unevenly while passing through the birth canal. In other cases, head shape changes after birth as a result of pressure on the back of the head when the baby lies on his or her back.

You'll notice two soft areas at the top of your baby's head where the skull bones haven't yet grown together. These spots, called fontanels, allow a baby's relatively large head to move through the narrow birth canal. They also accommodate your baby's rapidly growing brain during infancy.

Because your baby's skull is malleable, however, a tendency to rest the head in the same position can result in an uneven head shape well past the time when birth-related lopsidedness evens out. This is known as positional plagiocephaly.

What's normal and what isn't?

Positional molding might be most noticeable when you're looking at your baby's head from above. From that view, the back of your baby's head might look flatter on one side than on the other. The ear on the flat side might look pushed forward.

Is an uneven head shape cause for worry?

Positional molding is generally considered a cosmetic issue. Flat spots related to pressure on the back of the head don't cause brain damage or interfere with a baby's development.

Keep in mind that if you spend too much time worrying about your baby's head shape, you might miss some of the fun of being a new parent. In a few short months, better head and neck control will help your baby keep pressure more evenly distributed on the skull.

Positional molding

Because a baby's skull is malleable, a tendency to rest the head in the same position can result in an uneven head shape. The back of the head might look flatter on one side than on the other. This is known as positional plagiocephaly.

How is an uneven head shape treated?

Your child's doctor will do a physical exam to make a diagnosis of positional plagiocephaly. Changes in the way you position your baby can minimize unevenness and hasten its resolution. For example:

  • Change direction. Continue to place your baby on his or her back to sleep, but alternate the direction your baby's head faces when you place him or her in the crib. Or place your baby's head near the foot of the crib one day, the head of the crib the next. You might also hold your baby with alternate arms at each feeding. If your baby returns to the original position while sleeping, adjust his or her position next time.
  • Hold your baby. Holding your baby when he or she is awake will help relieve pressure on your baby's head from swings, carriers and infant seats.
  • Try tummy time. With close supervision, frequently place your baby on his or her tummy to play. Make sure the surface is firm.

Helmets and head shape

If unevenness doesn't improve with the help of repositioning by age 6 months or your baby is older than 8 months and has a severe deformity, your baby's doctor might prescribe a molded helmet to help shape your baby's head. A custom-fitted helmet relieves pressure on the flattened side of your baby's head.

Molded helmets are most effective when treatment begins between ages 4 and 12 months, when the skull is still malleable and the brain is growing rapidly. Treatment with a molded helmet isn't likely to be effective after age 1, when the skull bones are fused together and head growth becomes less rapid.

Molded helmet

A baby's skull is malleable. If necessary, a molded helmet might be used to help shape a baby's head. The helmet is worn at least 23 hours a day during the treatment period — often several months or even longer.

Beyond positional molding

Sometimes an underlying muscular issue — such as torticollis — causes a baby to hold his or her head tilted to one side. In this case, physical therapy is important to help stretch the affected muscles and allow the baby to more freely change head positions.

Rarely, two or more of the bony plates in a baby's head fuse prematurely. This rigidity pushes other parts of the head out of shape as the brain grows. This condition, known as craniosynostosis, is typically treated during infancy. To give the brain enough space to grow and develop, the fused bones must be surgically separated.

If you're concerned about your baby's head shape, check with your baby's doctor.

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