Babies have soft, pliable heads to move through the birth canal. However, many newborn head shapes appear slightly uneven, depending on their birth experience or how they sat in the uterus.

After bringing their sweet baby home, many parents evaluating their baby’s head shape want to know when to worry if a temporary unevenness may become permanent.

The good news is that most babies’ heads will round out on their own, and those who need help have many options from healthcare providers.

Understanding Baby’s Head Shape

Several factors contribute to a baby’s head shape. At birth and through infancy, babies have five major bones in their skull:

• Two frontal bones at baby’s forehead
• Two bones at the top of their head called parietal bones
• One bone in the back of their head called the occipital bone

At birth, babies’ heads include soft spots called fontanels and flexible spaces called sutures. The sutures meet at two fontanels, where the skull bones are still closing together.

Fontanels and sutures allow a baby’s large head to move through its mother’s narrow birth canal. They will also enable a baby’s skull to expand throughout infancy while their brain grows rapidly.

A baby’s skull continues to form until they’re about 9–18 months old. Toddler skulls are fully formed just before they begin to walk and run.

Is It Normal for a Baby’s Head to Be Uneven?

Many parents wonder about their babies’ head shapes: when to worry? First, it’s important to note that most babies’ heads round out independently. Additionally, an uneven head is typical for most babies after birth and considered completely normal. Most birth-related head shape issues resolve in about one to two weeks after delivery.

Additionally, in the first few months after delivery, babies’ head shapes continue to change, and babies may develop temporary flat spots from back sleeping or spending long periods in their car seat, stroller or rocker.

Causes of Uneven Babies’ Head Shapes: When to Worry

Many factors go into uneven shaping in a baby’s head. However, the most common causes of an irregular head shape are birth, positional head changes, being born prematurely, and congenital disabilities.

Birth

A baby’s birth experience often plays a role in their head shape. Commonly, babies delivered via cesarean section have more rounded heads than those who experience a vaginal birth, as they don’t need to squeeze through a long, narrow birth canal. However, many other birth factors affect a newborn’s head shape.

Babies whose mothers have a long labor may have a slightly uneven head from being squeezed regularly through contractions, regardless of whether they were born via C-section or vaginal birth.

Some babies will have a more cone-shaped head at birth if they spend extended time in the birth canal or if there is a lot of pressure inside the birth canal. The head’s cone-like shape results from squeezing during labor, which can push the skull bones over one another, giving the head a pointed shape.

Additional birth factors that may cause some newborn head molding include the use of forceps or vacuum birth. Babies who needed vacuum assistance to leave the birth canal may have a lump on their head from the suction, while babies whose delivery included forceps may have a slightly pinched look at the sides of their head.

When twins or other multiples have to share space in their mother’s uterus, lack of space may affect the evenness of their heads. Crowding in the womb often causes babies to move less and affects their head’s overall roundness even before labor or delivery.

Positional Head Changes

The safest way for babies to sleep in their crib is on their backs. However, this may cause a temporary flattening on the back of their head or at one side at one to two months old. Doctors refer to this particular head shape issue as positional plagiocephaly.

Positional plagiocephaly is a temporary condition often caused by back sleeping, extended time in a car seat, stroller, or rocker, or tight neck muscles (muscular torticollis) that drive the baby to turn their head to one side only.

Although it’s generally harmless, it’s natural to be concerned about a baby flat head. When to worry about this condition depends on a few factors. Parents can always discuss their concerns with a physician, but they will often see an improvement after their baby can sit up on their own.

Prematurity

Babies born prematurely are more likely to experience a flattened head shape because their skull is softer when they’re born. Additionally, lack of muscle control and strength makes premature babies more likely to rest their heads on one side at first.

Congenital Disabilities

A rare congenital disability called craniosynostosis occurs when a baby’s skull bones join together too early. Only affecting about one in every 2,500 newborns, craniosynostosis can lead to changes in a baby’s head shape and other complications.

How to Diagnose Abnormal Head Shape in Babies

Maintaining regular appointments with your pediatrician allows your provider to track your baby’s skull development. Your physician will first perform a visual exam on your baby’s skull to evaluate any unevenness, then may lightly feel for any variations on a baby’s normal skull shape.

If your pediatrician suspects craniosynostosis, they will likely refer you to a CT scan to see if your baby’s sutures fused prematurely.

Common abnormalities in a baby’s head shape not caused by craniosynostosis include plagiocephaly, brachycephaly, and scaphocephaly. All three conditions vary in severity. However, babies with mild forms of these head shape issues frequently find resolution through adjustments in routine pressure placed on the back or side of the baby’s head.

What is the Treatment? How to Shape Baby’s Head

Parents who want to know more about babies’ head shapes, when to worry about unevenness becoming permanent, or how to shape their baby’s head can make some general lifestyle adjustments that positively affect their baby’s head shape.

Babies with mild positional plagiocephaly benefit from:

• Alternating baby’s head position when sleeping
• Frequently changing baby’s location so their head position changes
• Carrying or wearing a baby in a carrier or sling often
• Practicing tummy time

It’s worth noting that physicians do not advise on how to shape a baby’s head with hands, as hand-shaping a baby’s skull can have some health risks, and any head shaping beyond the recommendations listed above should be done under medical care.

Babies who lack the roundness of a normal baby head shape at three months frequently benefit from interventions like the recommendations listed above.

Some parents may notice that baby’s head shape at six months still displays irregular shaping or flat spots. In that case, they may benefit from physical therapy or baby head shaping helmets to encourage a rounder and more symmetrical head shape.

Do Helmets Help Babies with Flat Heads?

When a baby’s head shape doesn’t round out on its own by about three or four months, a pediatrician may recommend using a cranial remolding helmet to reshape their head gently.

Using a helmet to shape a baby’s head is called helmet molding therapy or cranial orthosis. In helmet therapy, a custom baby helmet gently pushes against the broader parts of a baby’s head to mold the flatter parts into shape.

Babies undergoing helmet molding therapy typically wear helmets for up to 22 hours a day. This treatment usually lasts about three or four months.

What Is a Cranial Remolding Helmet?

A cranial remolding helmet or cranial orthosis treats head shape deformities in infants between 3 and 18 months of age. The younger a baby is at the start of treatment, the more effective helmet therapy is, as babies grow exceptionally fast in their first few months of life. At around 18 months of age, babies’ head shape becomes permanent.

Common head shape deformities that cranial remolding helmets remedy include plagiocephaly, brachycephaly, and scaphocephaly.

Cranial remolding helmets typically have a soft foam lining with a hard outer shell. Helmet therapy isn’t painful or uncomfortable for babies, and adjustments are made frequently to allow for the baby’s growth.

Babies with muscular torticollis who continue to lay on one side will no longer experience any cranial flattening on that side, as the helmet’s cushion prevents it.

All parents wondering about their baby’s head shapes/when to worry can rest assured that most babies’ heads quickly and naturally adjust into their regular roundness.

However, for those whose babies experience some malformation, treatments such as physical therapy and helmet therapy provide impressive results in shaping baby heads before they settle into a permanent shape.