The appearance of a flat spot on an infant’s head is a common observation that often prompts parental concern. A baby’s skull bones are soft and flexible, especially in the first few months, making them easily molded by external forces. This change in head shape is generally a consequence of prolonged time spent resting in the same position. Recognizing this frequent occurrence helps parents understand the cause of the flattening and shift focus from worry.
Understanding Head Shape Variations
The term “flat head syndrome” describes an atypical head shape that develops during the first year of life. The two main types of flattening are positional plagiocephaly and positional brachycephaly.
Positional plagiocephaly is the asymmetrical form, where flattening occurs on one side of the back of the head. This off-center pressure can cause the ear and forehead on the affected side to shift slightly forward, resulting in an uneven appearance.
Positional brachycephaly involves symmetrical flattening directly across the back of the head. This often results in a head that appears wider than usual, sometimes with a high or bulging forehead. These positional variations are considered cosmetic and do not typically affect a baby’s brain development or neurological health.
Common Positional Causes
The increased frequency of positional head flattening is primarily driven by the “Back to Sleep” campaign, which recommends placing infants on their backs to sleep to reduce the risk of Sudden Infant Death Syndrome (SIDS). While this practice has dramatically lowered SIDS rates, it means infants spend more time resting on the back of their heads, increasing the potential for pressure-induced changes.
This back-lying time is often extended by the use of modern infant equipment, such as car seats, bouncers, and swings. Prolonged periods in these devices cause constant pressure on the same area of the skull, restricting head movement. The skull is most susceptible to molding during the first four months of life while the bones are rapidly growing and still relatively soft.
Congenital muscular torticollis is an underlying risk factor for developing an uneven head shape. This condition involves tightness or shortening in one of the neck muscles, making it difficult for the infant to turn their head away from a favored side. The baby consistently rests the head in the same orientation, leading directly to the development of a flat spot. Addressing this muscle imbalance is important for successfully correcting the head shape.
Proactive Repositioning and Prevention
The most effective strategy for preventing and treating mild flattening is repositioning, which involves making conscious changes to how the baby rests and plays. The most widely recommended activity is supervised “Tummy Time.” This relieves pressure on the back of the skull while strengthening the neck and upper-body muscles. Parents should start Tummy Time soon after birth, beginning with short, several-minute sessions daily, aiming for 15 to 30 minutes total throughout the day by about seven weeks of age.
Other repositioning techniques help shift pressure points:
- Actively reduce the amount of time an infant spends in stationary equipment like car seats and swings when not traveling.
- When placing the baby in the crib for sleep, alter the direction the baby faces each night to encourage looking out into the room from a different angle.
- During feeding, alternate the arm used to hold the baby to encourage turning the head to both sides.
- When carrying the baby, use different holds, such as the “football hold” across the arm, to take pressure off the back of the head.
Identifying Severe Cases and Medical Options
While most flat spots are positional, a misshapen head can rarely signal craniosynostosis. This is an uncommon condition where one or more of the fibrous joints, or sutures, between the skull plates prematurely fuse together. Unlike positional flattening, which develops after birth from external pressure, craniosynostosis is congenital and can restrict normal skull growth, potentially affecting brain development and often requiring surgical intervention.
A pediatrician should be consulted if the flattening appears severe, if there is noticeable asymmetry in facial features, or if the infant struggles to turn the head to one side, which may indicate torticollis.
For moderate to severe positional flattening that does not improve with repositioning efforts by about six months of age, medical options may be discussed. Treatment often begins with physical therapy to address underlying muscle tightness associated with torticollis. In persistent cases, a cranial orthotic helmet may be recommended to gently redirect the baby’s rapid head growth toward the flatter areas, thereby reshaping the skull.