The official term is “positional plagiocephaly,” but most parents identify the condition as a flat spot on their baby’s head, and, according to a new study, more babies may have it than once thought. Canadian researchers found that nearly half — 47 percent — of the 7-12 week old infants in their study cohort had some form of plagiocephaly.

The study results were published online July 8 in the journal Pediatrics. Researchers studied 440 infants in four community health centers in Calgary, Alberta.

The majority of cases identified were mild. More severe cases can be treated with a special helmet. If it goes untreated, the spot can become permanent and potentially change facial features.

Some of the reasons pointed to as the cause include the birthing process; keeping babies in devices like car seats or bouncy chairs; and putting babies “back to sleep” to prevent Sudden Infant Death Syndrome (SIDS) and other sleep-related deaths.

Parents can avoid flat spots by moving their babies. Tummy time can get babies off their backs while helping to strengthen the neck, shoulder and arm muscles.