Infant plagiocephaly, or flat head syndrome, is position-related flattening of the skull. The French National Authority for Health (HAS) considers it benign and notes that it most often resolves on its own by around the age of two. Prevention relies on simple measures, without ever abandoning back sleeping.
What is positional plagiocephaly?
Positional plagiocephaly is a skull deformity caused by prolonged pressure on the same spot. An infant's skull is soft and molds under pressure. When the head often rests on the same side, one area becomes flattened.
The HAS refers to "positional skull deformities" (DCP). This term includes plagiocephaly and other flattening of the same type. It is a common phenomenon and, in the vast majority of cases, is not serious.
What does the HAS recommend to prevent flat head syndrome?
The HAS recommends putting babies to sleep on their backs while varying the points of pressure on their heads during the day. Children should also be allowed to move freely when they are awake and supervised. These recommendations date from March 2020.
Always put your baby to sleep on their back
Back sleeping remains essential every time your baby sleeps. According to the HAS, it is the only way to prevent sudden unexpected infant death. Fear of flat head syndrome should never lead to putting a baby to sleep on their stomach.
Vary pressure points and provide tummy time
During wakeful periods, encourage your baby to turn their head in both directions. Alternate their position in the crib and during play. Tummy time, while awake and supervised, relieves pressure on the back of the skull and strengthens the neck.
Limit time spent in carriers and reclining seats
The HAS recommends reducing the time spent in bouncers, carriers and seats. These supports keep the head pressed against the same spot. The floor remains the best place for moving and changing pressure points.
Should you use a pillow or flat-head support?
No. The HAS advises against head positioners, flat-head pillows and head supports. These devices restrict the child's spontaneous movements. They therefore run counter to the intended goal.
Prevention relies on free movement, not on an accessory. By moving, babies naturally distribute pressure across their skull.
Does plagiocephaly affect development?
The HAS is clear on this point: no causal link has been demonstrated. Positional plagiocephaly does not cause delays in neurological development. Nor is it associated with ophthalmological, oculomotor or vestibular disorders.
This clarification is intended to reassure parents. The deformity is primarily an aesthetic issue that diminishes as the child grows. It should not be a source of excessive worry.
When should you consult a doctor?
Medical advice is useful if the flattening worsens despite positional measures. Difficulty turning the head to one side, suggesting torticollis, also warrants an examination. The doctor or pediatrician will then assess the situation.
If the deformity persists, early referral to a specialized center is possible. The use of a cranial orthosis remains exceptional and should be based on specialist advice.
How should you arrange your baby's floor time?
Floor time is at the heart of prevention. A clean, flat and cushioned space encourages your baby to move and change pressure points. This is where tummy time and free movement take place.
An activity mat provides a suitable surface for these moments of floor play. To apply the principle recommended by the HAS, read our article on free movement. The choice of mat material also matters: our foam mat guide details the key safety considerations.
Back sleeping remains the rule for sleep. Our guidance on safe infant sleep complements these recommendations. To follow motor development milestones, also see our article on fine and gross motor skills.
Why are flat heads more common today?
Back sleeping has significantly reduced sudden unexpected infant death since the 1990s. This public health measure has saved many lives. In return, infants spend more time with pressure on the back of their skulls.
That is why the HAS emphasizes daytime wakefulness. The message is not to put babies to sleep in another position, but to increase tummy time and floor time. This preserves the benefits of back sleeping while limiting flattening.
In summary
Infant plagiocephaly is common, benign and usually reversible. The HAS recommends back sleeping, varying pressure points and floor time. It advises against corrective pillows and reassures parents that there are no effects on development.
Sources
- French National Authority for Health, "Preventing plagiocephaly without increasing the risk of sudden unexpected infant death", March 5, 2020.
- French National Authority for Health, recommendations "Prevention of positional skull deformities (DCP) and sudden unexpected infant death", 2020.
