At a glance
- Always put your baby on the back to sleep, even if a flat spot appears.
- Start supervised tummy time the day your baby comes home: 3 to 5 minutes, 2 to 3 times a day.
- Build up to 15 to 30 minutes of tummy time a day by 7 weeks of age.
- Limit time in car seats, swings, bouncers and carriers when not traveling.
- A head that always turns one way may mean torticollis, which is treated with physical therapy.
- Most flat spots round out as babies grow and start sitting up.
- A helmet is considered only for moderate or severe flattening not better by 5 or 6 months.
Why flat spots happen
A baby’s skull plates are soft and can shift, so steady pressure on one spot flattens it. Flattening most often develops in the first 4 to 12 weeks of life, and in about 20% of babies it begins in the womb or during birth.
It is more likely in babies who favor one side, get little tummy time, were born early, are twins or triplets, or had a forceps or vacuum delivery.
Back sleeping can add to flat spots, but a flat spot is far less serious than SIDS. Keep placing your baby on the back for every sleep.
Types of head shape changes
Positional flattening is not the same as craniosynostosis, a rarer condition in which skull seams close too early. Only your pediatrician can tell them apart, and positional shapes do not need surgery.
Common head shapes
- One side of the back is flatter
- Forehead may stick out more
- Whole back of the head is flat
- Head looks wide from side to side
- Common in preemies after a long NICU stay
Tummy time and repositioning
- Place your baby on the back for every sleep, on a firm, flat surface with no pillows, wedges or positioners.
- Begin tummy time on the first day home, always while your baby is awake and watched.
- Try it after a diaper change or a nap, when your baby is calm and alert.
- Over the following months, work toward about an hour a day, split into several short sessions.
- Switch the end of the crib your baby’s head faces, since babies turn toward light and activity.
- Switch arms when holding, and change sides when breastfeeding or bottle-feeding.
- Hold your baby upright and play together on the floor instead of leaving them in seats or swings.
Tummy time as your baby grows
- First day home3 to 5 minutes, 2 to 3 times a day.
- By 7 weeks15 to 30 minutes a day in total.
- The months afterWork toward about an hour a day in short sessions.
- 5 or 6 monthsModerate or severe flattening not improving: ask about a specialist.
- Sitting upLess time lying down; most flat spots round out.
Head-turn preference and torticollis
If your baby always looks to one side or tilts the head, tight neck muscles (torticollis) may be the cause. About 85% of babies with torticollis also have a flat spot.
Your pediatrician may refer your baby to early intervention or a pediatric physical therapist, who teaches stretches and positioning to do at home. Some babies need weekly therapy.
When is a helmet needed?
Mild flattening usually improves with repositioning and tummy time alone. A molding helmet is considered for moderate or severe flattening that has not responded by 5 or 6 months, and it is fitted by a specialist.
When to see the pediatrician
- The flat spot is getting worse despite repositioning.
- Your baby always turns one way, tilts the head or has trouble turning the neck.
- The head shape looks unusual, not just flat at the back or side.
- Your baby seems behind in holding up the head, rolling or other motor skills.
Flat head: when to get help
- Call 911Hard to wake, trouble breathing or a seizure; these are not from a flat head.
- See the pediatricianWorsening flat spot, head always turned one way, unusual shape or slow motor skills.
- At homeBack to sleep, tummy to play, and change positions through the day.
Common questions
Will my baby’s flat head go away?
Usually. Mild flattening tends to fade once babies sit and spend less time lying on their backs.
Can my baby sleep on the tummy to fix a flat spot?
No. Back sleeping protects against SIDS, which matters far more; use awake tummy time instead.
How much tummy time does a newborn need?
A few minutes at a time, two or three times daily at first, adding up to 15 to 30 minutes a day by about 7 weeks.
Do flat head pillows or sleep positioners help?
No. The AAP and FDA advise never using sleep positioners or wedges, because they have not been shown to be safe.
When does a baby need a helmet for a flat head?
Only when marked flattening has not responded to other measures by 5 or 6 months; a specialist decides and does the fitting.
Is a flat head a sign of a brain problem?
Usually not; it is a change in skull shape. The pediatrician can check for craniosynostosis, a rarer condition where skull seams close early.
Sources
- AAP — When a Baby’s Head is Misshapen: Positional Skull Deformities
- AAP — Back to Sleep, Tummy to Play
- AAP — Putting Back-Sleeping Concerns to Rest
- NICHD — Other SIDS FAQs
Written for Pedemy in our own words from the sources above; checked October 2026. For education only, not medical advice. Pedemy is independent and not affiliated with or endorsed by the organizations cited.