Mayo Clinic Health Library

Baby's head shape: What's normal?

Updated: 01-21-2012

Many newborns have slightly lopsided heads. 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. Although your baby's head shape will probably even out on its own, you can help prevent flat spots — and detect more-serious problems.

How position affects head shape

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 or positional molding.

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 cheekbone on the flat side might protrude, and the ear on the flat side might look pushed forward.

What you can do about it

Babies who spend most of their time on their backs in cribs, car seats or infant seats are more likely to develop positional molding. Although positional molding often resolves on its own as a baby's head and neck control improves, you can take steps now to encourage a more even head shape. 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. Don't worry if your baby returns to the original position while sleeping. Simply adjust his or her position the 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, place your baby on his or her tummy to play. Make sure the surface is firm. If you must leave the room, bring your baby with you.
  • Get creative. Position your baby so that he or she will have to turn away from the flattened side of the head to look at you or to track movement or sound in the room. Move the crib occasionally to give your baby a new vantage point. Never rest your baby's head on a pillow or other type of soft bedding.

Helmets and head shape

Varying a baby's head position is typically enough to prevent or treat flat spots. If the lopsidedness doesn't improve by age 4 months, your baby's doctor might prescribe a special molded helmet to help shape your baby's head. These devices work by applying gentle but constant pressure in an effort to redirect skull growth.

Molded helmets are most effective when treatment begins by ages 4 to 6 months, when the skull is still malleable and the brain is growing rapidly. To be effective, the helmet must be worn 23 hours a day during the treatment period — often a number of months. The helmet is adjusted regularly — sometimes weekly — as the baby's head grows and changes shape. Treatment with a molded helmet isn't likely to be effective after age 1, when the skull bones are fused together.

Keep in mind that 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 growth and development.

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 can 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 expands. 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.

Keep it in perspective

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. Until then, change your baby's position as often as it's practical to do so. If you're concerned about your baby's head shape, check with your baby's doctor.