Physical Development

Preventing Flat Spots on Baby's Head (Plagiocephaly)

Medically reviewed by Dr. Sarah Chen, MD, FAAP · Board-Certified Pediatrician

Content reviewed against published AAP, NIH guidelines

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Your baby's physical development is unique, and concerns about preventing flat spots on baby's head (plagiocephaly), here is what you need to know.

The short answer

Flat spots on a baby's head (positional plagiocephaly) are very common because newborn skulls are soft and malleable. Prevention strategies include regular tummy time when awake, alternating head position during sleep, and minimizing time in car seats and bouncers when not traveling. Most mild flat spots improve on their own as baby grows.

Key takeaways

  • Flat spots on a baby's head (positional plagiocephaly) are very common because newborn skulls are soft and malleable. Prevention strategies include regular tummy time when awake, alternating head position during sleep, and minimizing time in car seats and bouncers when not traveling. Most mild flat spots improve on their own as baby grows.
  • Usually normal when: Mild flattening on one side or the back of the head
  • Call your doctor if: Severe or rapidly worsening head shape asymmetry
  • Varies by age — see the age-by-age breakdown below
Supervised tummy time is recommended daily from the time the baby comes home from the hospital to help prevent flat head syndrome and to strengthen neck and shoulder muscles.
Back to Sleep, Tummy to Play, American Academy of Pediatrics (AAP)

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What Parents Should Know

According to AAP, NIH guidelines, flat spots on a baby's head (positional plagiocephaly) are very common because newborn skulls are soft and malleable. Prevention strategies include regular tummy time when awake, alternating head position during sleep, and minimizing time in car seats and bouncers when not traveling. Most mild flat spots improve on their own as baby grows. At 0-1 month, a baby's skull is made of soft, flexible bones that can become flattened from sustained pressure in one position. Since babies must sleep on their backs for safety, some flattening is common. Prevention strategies from birth: alternate which direction baby's head faces during sleep (babies tend to look toward the room or light, so alternate which end of the crib their head is at), provide supervised tummy time starting from day one (even a few minutes several times a day), alternate which arm you use for feeding and holding, and limit time in car seats, swings, and bouncers when baby is not traveling. If baby has a strong head-turning preference, address it early with repositioning. It is generally considered normal when mild flattening on one side or the back of the head. However, you should contact your pediatrician promptly if severe or rapidly worsening head shape asymmetry.

Sources: [1], [2]

Normal vs. Concerning

Usually Normal
Worth Discussing
Mild flattening on one side or the back of the head
Severe or rapidly worsening head shape asymmetry
Flat spot improves as baby increases tummy time and upright play
Head shape changes with a bulging fontanelle, vomiting, or irritability, which could indicate increased intracranial pressure rather than positional flattening
Baby has no positional preference or torticollis contributing to the flat spot
Concern that the skull sutures may be fusing prematurely (craniosynostosis): a ridge along the skull or abnormal head shape present at birth

By Age

What to expect by age

0-1 month

A baby's skull is made of soft, flexible bones that can become flattened from sustained pressure in one position. Since babies must sleep on their backs for safety, some flattening is common. Prevention strategies from birth: alternate which direction baby's head faces during sleep (babies tend to look toward the room or light, so alternate which end of the crib their head is at), provide supervised tummy time starting from day one (even a few minutes several times a day), alternate which arm you use for feeding and holding, and limit time in car seats, swings, and bouncers when baby is not traveling. If baby has a strong head-turning preference, address it early with repositioning.

1-3 months

This is when flat spots most commonly develop and become noticeable. Increase tummy time gradually, aiming for 15-30 minutes total per day by 2 months. When baby is on their back, use toys and your voice to encourage looking in both directions. Your pediatrician will monitor head shape at well-visits. If a flat spot is developing, they may recommend increased repositioning, tummy time, or evaluation for torticollis, which is a common contributing factor.

3-6 months

As baby gains head control and spends more time upright, flat spots often begin to improve naturally. If a significant flat spot has not improved with repositioning by 4-6 months, your pediatrician may discuss referral for a cranial molding helmet. Helmet therapy is most effective between 4-8 months when the skull is still rapidly growing and most malleable. Not all flat spots require a helmet; many improve on their own.

6-12 months

Most mild to moderate flat spots continue to improve as baby spends more time sitting, crawling, and upright. Skull growth slows after 12 months, so significant improvements from repositioning alone become less likely. Helmet therapy, if needed, is typically completed by 12 months. Hair growth also helps camouflage remaining mild asymmetry. Long-term outcomes are excellent for the vast majority of children.

What to Tell Your Pediatrician

  • Describe when you first noticed preventing flat spots on baby's head (plagiocephaly) and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if you notice a flat spot developing on one side or the back of the head.
  • Mention if the flat spot seems to be worsening despite repositioning.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

What Should You Do?

When to take action

Probably normal when...
  • Mild flattening on one side or the back of the head
  • Flat spot improves as baby increases tummy time and upright play
  • Baby has no positional preference or torticollis contributing to the flat spot
Mention at your next visit when...
  • You notice a flat spot developing on one side or the back of the head
  • The flat spot seems to be worsening despite repositioning
  • Baby has a strong head-turning preference that may be contributing to the flat spot
Act now when...
  • Severe or rapidly worsening head shape asymmetry
  • Head shape changes with a bulging fontanelle, vomiting, or irritability, which could indicate increased intracranial pressure rather than positional flattening
  • Concern that the skull sutures may be fusing prematurely (craniosynostosis): a ridge along the skull or abnormal head shape present at birth

What You Can Do at Home

  • Keep track of when you notice preventing flat spots on baby's head (plagiocephaly) — noting the time of day, duration, and any triggers can help your pediatrician.
  • Remember that mild flattening on one side or the back of the head — this is generally within the range of normal.
  • At 0-1 month, focus on observation rather than intervention unless your pediatrician advises otherwise.
  • Provide plenty of supervised floor time and tummy time to support your baby's physical development.
  • While monitoring at home, seek immediate care if severe or rapidly worsening head shape asymmetry.

Frequently asked questions

Is preventing flat spots on baby's head (plagiocephaly) normal?
Flat spots on a baby's head (positional plagiocephaly) are very common because newborn skulls are soft and malleable. Prevention strategies include regular tummy time when awake, alternating head position during sleep, and minimizing time in car seats and bouncers when not traveling. Most mild flat spots improve on their own as baby grows.
When should I call the doctor about preventing flat spots on baby's head (plagiocephaly)?
Severe or rapidly worsening head shape asymmetry Head shape changes with a bulging fontanelle, vomiting, or irritability, which could indicate increased intracranial pressure rather than positional flattening Concern that the skull sutures may be fusing prematurely (craniosynostosis): a ridge along the skull or abnormal head shape present at birth
When is preventing flat spots on baby's head (plagiocephaly) normal?
Mild flattening on one side or the back of the head Flat spot improves as baby increases tummy time and upright play Baby has no positional preference or torticollis contributing to the flat spot
What causes preventing flat spots on baby's head (plagiocephaly)?
Flat spots on a baby's head (positional plagiocephaly) are very common because newborn skulls are soft and malleable. Prevention strategies include regular tummy time when awake, alternating head position during sleep, and minimizing time in car seats and bouncers when not traveling. Most mild flat spots improve on their own as baby grows. Common explanations include: Mild flattening on one side or the back of the head. Flat spot improves as baby increases tummy time and upright play.
What should I mention to my pediatrician about preventing flat spots on baby's head (plagiocephaly)?
You should mention preventing flat spots on baby's head (plagiocephaly) at your next visit if: You notice a flat spot developing on one side or the back of the head. The flat spot seems to be worsening despite repositioning. Baby has a strong head-turning preference that may be contributing to the flat spot.
Is preventing flat spots on baby's head (plagiocephaly) normal at 0-1 month?
A baby's skull is made of soft, flexible bones that can become flattened from sustained pressure in one position. Since babies must sleep on their backs for safety, some flattening is common. Prevention strategies from birth: alternate which direction baby's head faces during sleep (babies tend to look toward the room or light, so alternate which end of the crib their head is at), provide supervised tummy time starting from day one (even a few minutes several times a day), alternate which arm you use for feeding and holding, and limit time in car seats, swings, and bouncers when baby is not traveling. If baby has a strong head-turning preference, address it early with repositioning.
Is preventing flat spots on baby's head (plagiocephaly) normal at 1-3 months?
This is when flat spots most commonly develop and become noticeable. Increase tummy time gradually, aiming for 15-30 minutes total per day by 2 months. When baby is on their back, use toys and your voice to encourage looking in both directions. Your pediatrician will monitor head shape at well-visits. If a flat spot is developing, they may recommend increased repositioning, tummy time, or evaluation for torticollis, which is a common contributing factor.
Should I go to the ER for preventing flat spots on baby's head (plagiocephaly)?
Seek emergency care if severe or rapidly worsening head shape asymmetry, or if head shape changes with a bulging fontanelle, vomiting, or irritability, which could indicate increased intracranial pressure rather than positional flattening. When in doubt, call your pediatrician's after-hours line for guidance.
Does preventing flat spots on baby's head (plagiocephaly) go away on its own?
In many cases, preventing flat spots on baby's head (plagiocephaly) resolves on its own, especially when mild flattening on one side or the back of the head. By 6-12 months, most mild to moderate flat spots continue to improve as baby spends more time sitting, crawling, and upright. Skull growth slows after 12 months, so significant improvements from repositioning alone become less likely. Helmet therapy, if needed, is typically completed by 12 months. Hair growth also helps camouflage remaining mild asymmetry. Long-term outcomes are excellent for the vast majority of children.

References

  1. [1]American Academy of Pediatrics. Prevention and Management of Positional Skull Deformities in Infants. Pediatrics. 2011. AAP
  2. [2]National Library of Medicine. Positional Plagiocephaly. StatPearls. NIH

Doctor Visit Checklist

Bring this checklist to your next pediatrician visit to discuss Preventing Flat Spots on Baby's Head (Plagiocephaly).

Things to mention

  • Describe when you first noticed preventing flat spots on baby's head (plagiocephaly) and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if you notice a flat spot developing on one side or the back of the head.
  • Mention if the flat spot seems to be worsening despite repositioning.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

Observations to share

  • You notice a flat spot developing on one side or the back of the head
  • The flat spot seems to be worsening despite repositioning
  • Baby has a strong head-turning preference that may be contributing to the flat spot

Urgent signs to report immediately

  • Severe or rapidly worsening head shape asymmetry
  • Head shape changes with a bulging fontanelle, vomiting, or irritability, which could indicate increased intracranial pressure rather than positional flattening
  • Concern that the skull sutures may be fusing prematurely (craniosynostosis): a ridge along the skull or abnormal head shape present at birth

My notes

From ismybabyalright.com — free, evidence-based baby health guides

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members

Bottom line

Most cases of preventing flat spots on baby's head (plagiocephaly) are normal. Talk to your pediatrician if severe or rapidly worsening head shape asymmetry.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

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Baby Prefers One Position (Positional Preference)

Many newborns develop a preference for turning their head to one side, which is common and often resolves with simple repositioning strategies. However, a persistent preference may indicate torticollis (tightness in neck muscles), which responds well to stretching exercises and physical therapy when addressed early.

When to Start Tummy Time

Tummy time can and should start from day one. The AAP recommends supervised tummy time from the first day home. For newborns, this can be as simple as placing baby on your chest while you recline, or brief sessions on a firm surface for 1-3 minutes several times a day. Tummy time is essential for developing head control, strengthening muscles, and preventing flat spots.

Safe Sleep Position for Newborns

The safest sleep position for babies is on their back, on a firm flat surface, for every sleep. This recommendation from the AAP significantly reduces the risk of SIDS and sleep-related deaths. Always place your baby on their back until they can roll both ways independently.

Should I Use Adjusted Age for My Preemie's Milestones?

Yes — for premature babies, developmental milestones should be assessed using adjusted (corrected) age, not chronological age, until at least 2 years of age. Adjusted age is calculated by subtracting the number of weeks your baby was born early from their actual age. For example, a 6-month-old born 2 months early would have an adjusted age of 4 months, and should be assessed against 4-month milestones. Most pediatricians use adjusted age for developmental assessment through age 2-3, and for growth charts through age 2.

Baby-Proofing a Small Apartment

Baby-proofing a small apartment is absolutely possible and focuses on the same key safety principles as any home: securing furniture to walls, covering outlets, locking cabinets with hazardous materials, and ensuring safe sleep spaces. Small spaces actually have an advantage - there is less area to monitor. Focus on eliminating the most dangerous hazards first: falls, poisoning, choking, and burns.

My Baby Seems to Use One Side More Than the Other

Babies should use both sides of their body fairly equally during the first 18 months of life. While slight preferences can be normal, a consistent pattern of favoring one side - using one arm much more than the other, crawling with one leg dragging, or turning the head predominantly one way - should always be discussed with your pediatrician. Early identification of asymmetry leads to the best outcomes.