It can be alarming to see that your baby’s head has suddenly gone a bit flat, especially on the back, but don’t worry: in the vast majority of cases, this is nothing to worry about. Newborn skulls are much softer than an adult’s head as the bones are not yet fused together. As a result, babies who sleep on their backs often experience a strange looking flattening of the bones in the back of their heads. This condition is called positional plagiocephaly.
Although positional plagiocephaly is not dangerous, you can take a few steps to avoid it, all involve stimulating the baby to rotate the head in both directions:
- Change your baby’s position in the crib at regular intervals (by pointing the feet in different directions).
- Change your baby’s head position during feeding, so as not to place too much pressure on one side of the skull.
- Minimizing baby’s time in car seats, bouncers and carriers as they limit the range of motion of the head.
In the vast majority of cases, the slight flattening of the skull will have no effect on a child’s brain development, and the affected area of skull will round out naturally as the baby approaches toddlerhood and spends less and less time on the back. In rare cases, plagiocephaly can become quite noticeable, with a sloping forehead or obvious asymmetry of the back of the head. If this happens, your pediatrician will send you to a specialist in plagiocephaly. There, they will measure the head in all angles and determine if pressure bands or a special helmet should be used to correct the problem. They will also examine the baby’s neck for signs of torticollis or a tightening of one or more muscles that limits the baby’s range of motion.
While it’s true that stomach sleepers have much less plagiocephaly than babies put to bed on their backs, one thing you should not do is to lay baby down on their stomach to sleep. Sleeping on the stomach increases the risk of sudden infant death syndrome (SIDS). Since 1992, when the American Academy of Pediatrics (AAP) began recommending that babies sleep on their backs instead of their tummies, the incidence of SIDS has decreased. The risk of positional plagiocephaly does NOT outweigh the risk of SIDS.
Reviewed by Dr. Sara Connolly, July 2019