Nearly half of babies under 2-months-old have a flat spot on the back of their heads, according to a new Canadian study published Monday in the journal Pediatrics.

According to the findings, positional plagiocephaly affected 46.6 percent of two-month-old babies involved in the study. Previous studies conducted in the U.S. and Europe have shown the condition in 3 percent to 61 percent of babies, lead author Aliyah Mawji of Calgary’s Mount Royal University told the Toronto Star.

The study pointed to an education campaign called “Back To Sleep” launched in 1992, which encouraged parents to have their babies sleep on their backs to decrease instances of Sudden Infant Death Syndrome (SIDS). While the United States experienced a 50 percent decrease in the infant mortality rate, more infants experienced positional plagiocephaly -- where the baby’s head is misshapen from spending too much time on their backs, USA Today reports.

"This is super common," said Dr. Lisa Stellwagen, a neonatologist from the University of California, San Diego School of Medicine, who was not involved in the study but has studied the condition, told Reuters. "With the Back To Sleep [campaign] and the overuse of car seats, and people not holding their babies like they used to, we've sort of rediscovered this problem with infants' head shapes."

The study followed 440 infants between 7 to 12 weeks old over a period of three months in Calgary, Alberta. Out of the study’s participants, 205 had plagiocephaly. More than half had symptoms on the right side of their skull.

Carly Titus from Quebec noticed her daughter, Nelly Paradis, had the condition when she started to favor one side of her neck. At 5 months old she had to wear a plastic helmet to correct the condition.

“When you looked down on her, you could see -- her skull had developed like a crooked ball,” Titus told the Toronto Star. “One of her cheeks was bigger, and her eyes were not symmetrical. Everything was not symmetrical.”

Babies’ skulls are malleable because they are not made of one bone but held together by cartilage that allows them to squeeze through the birth canal. If infants are kept in the same position for a significant amount of time, they will develop a flat spot. While plagiocephaly doesn’t damage the brain, it can be permanent, Dr. Claire McCarthy, a pediatrician and medical communications editor at Boston Children’s Hospital, says.

McCarthy recommends altering the infant’s position during the day by encouraging “tummy time” and using a baby sling to carry the child. At night, try to alternate which side the baby rests his or her head.  

Despite awareness campaigns surrounding the condition, Mawji says many parents need to take better preventative action.

“We found that parents were not getting the message that even though they need to put babies to sleep on their back, they need to turn their heads,” she said.