Passage through the birth canal often makes a newborn's head appear pointy or elongated for a short time. It's normal for a baby's skull, which is made up of several separate bones that will eventually fuse together, to be slightly misshapen during the few days or weeks after birth.
But if you've noticed that your baby is developing a persistent flat spot, either in the back or on one side of the head, it could be a sign of positional plagiocephaly. Also known as flattened head syndrome, this can occur when a baby sleeps in the same position repeatedly or because of problems with the neck muscles.
Fortunately, positional plagiocephaly usually is easy to treat, and with appropriate intervention will correct itself by the time a child is 1 year old.
About Positional Plagiocephaly
Positional plagiocephaly is a disorder in which the back or one side of an infant's head is flattened, often with little hair growing in that area. It's most often the result of babies spending a lot of time lying on their backs or often being in a position where the head is resting against a flat surface (such as in cribs, strollers, swings, and playpens).
Because infants' heads are soft to allow for the incredible brain growth that occurs in the first year of life, they're susceptible to being "molded" into a flat shape.
The number of positional plagiocephaly cases increased sixfold from 1992 to 1994, occurring in approximately 33 out of every 10,000 births. This dramatic increase started when the American Academy of Pediatrics (AAP) began its "Back to Sleep" campaign, which continues to recommend that babies sleep on their backs to reduce the risk of sudden infant death syndrome (SIDS).
Since the AAP's campaign, the incidence of SIDS in the United States has decreased by almost 40% while the incidence of flattened head syndrome has risen. Still, the prevention of SIDS is worth the increased risk of a flattened head, especially because positional plagiocephaly will often correct itself with appropriate intervention.
Causes of Positional Plagiocephaly
The most common cause of a flattened head is a baby's sleep position. Because an infant sleeps so many hours on the back of his or her head, the head sometimes assumes a flat shape.
Another thing that can contribute to flattening is torticollis, which means the neck muscles are too tight, have inadequate tone, or are shorter on one side than the other, causing the head to tilt one way while the chin points in the opposite direction.
Premature babies are more prone to positional plagiocephaly — their skulls are softer than those of full-term babies, and they spend a great deal of time on their backs without being moved or picked up because of their medical needs and extreme fragility after birth, which usually requires a stay in the neonatal intensive care unit.
A baby might even start to develop positional plagiocephaly before birth, if pressure is placed on the baby's skull by the mother's pelvis or a twin. In fact, it's not at all unusual to see plagiocephaly in multiple birth infants.
But the differences in head shape seen in children with positional plagiocephaly shouldn't be confused with those caused by craniosynostosis, a more serious condition that occurs when skull bones fuse together too soon, causing an abnormal skull shape and possible brain damage if the condition is not corrected. A child with craniosynostosis may have deformities in the front of the head and a bony ridge over the abnormally fused skull bones. Craniosynostosis is usually corrected with surgery.
Signs and Symptoms
Positional plagiocephaly is usually easy for parents to notice. Typically, the back of the child's head (called the occiput) and the ear on the flattened side may be pushed forward. In severe cases, there may be bulging on the side opposite from the flattening and the forehead may be asymmetrical (or uneven), although this is unusual in full-term infants. If torticollis is the cause, the neck, jaw, and face may be asymmetrical.
Most often, a doctor can make the diagnosis of positional plagiocephaly simply by e