Maggie Fox, Senior WriterNBC News
About half of all 2-month-old babies screened in a study had flat spots on their heads, Canadian researchers reported Monday in one of the first studies aimed at assessing just how common the problem is.
The culprit – or culprits – are likely all the devices designed to hold babies safe and still, the team at Mount Royal University in Calgary reported.
"The reason why we want to catch this early is because if we see children with flattened heads, sometimes there are changes in their facial features," says Aliyah Mawji, a registered nurse at the university who led the study.
Pediatricians and pediatric nurses have noticed a big increase in the number of babies with flat spots on their heads – a condition known as positional plagiocephaly ("oblique head" in Greek).
Most experts say it's due to advice to put babies to sleep on their backs – which in turn has slashed rates of sudden infant deaths syndrome or SIDS. But babies have big, heavy heads and weak little necks, which means their heads tend to roll to one side. Because their skulls are still soft, this can cause a flat spot.
Terri Peters of Pasadena, Md. says it happened to her daughter Kennedy. "She was such a low-key, easy baby," says Peters, who blogged about Kennedy's progress.
"She smushed one side of her head down and slept in one spot in that seat for two months and and I didn't think anything of it because she was a good baby and we had a toddler and we had just moved into a new house," adds Peters. "She would tuck her little head into her shoulder."
At two months, the pediatrician noticed. "I didn't see it," says Peters. "I was in complete denial." But when she looks at baby pictures of Kennedy, now nearly 3, she can tell. "It was on the right side of her head. Her eye was squinty on one side. If you looked at her two ears, one was a little displaced from the other one."
When Mawji researched the issue, she couldn't find any studies that gave hard and fast numbers of just how common this is in babies. "This was really surprising," she said in a telephone interview.
So she and colleagues did a survey in four Calgary clinics where parents bring their babies – each in a different type of neighborhood. They looked at 440 babies aged 7 to 12 weeks. "We found that 46.6 percent actually had some form of plagiocephaly," Mawji says.
A slight majority, 63 percent, had the flat spot on the right, and Mawji says that comes from the moment of birth.
"This is actually due to the birthing process itself," Mawji says. "The majority of infants come out in such a way that their head is turned to the right." This is in part because the mother's pelvic bone and spine don't move – they're hard bones – so the more flexible baby ends up squished and twisted.
If a baby doesn't move around enough, this flat spot can become more permanent. And if no one does anything, and the skull hardens, it could become really permanent.
Most of the cases Mawji saw were mild. And while she took care to get a range of family types into her study, she stresses that more research is needed to really show how common the issue is across the larger North American population. But her findings show it is probably more common than most people thought.
So what can parents do? Move the child, Mawji advises.
"Even though it is still important to put your baby to sleep on the back to prevent SIDS, it is important to vary the side of the head that is down," she says. "If you notice that one night when you put your baby down, the head is to the right, you want to make sure that the next night you are turning the head to the left side," she said.
"And be mindful of devices or holding positions that put pressure on infant's head." That includes car seats and bouncy chairs. Parents and caregivers should make sure they are not always holding the baby in the same position at feeding time.
"Also, tummy time is important, too," Mawji adds. When changing the baby, or playing, a few minutes on the tummy can help strengthen the head, neck, belly and arms.
"Parents aren't getting the message they should be doing these things," Mawji says.
Children with severe cases may need to wear a special orthotic helmet. These often must be custom-made to fit the child and can cost thousands of dollars.
Kennedy got a pink one. "She wore it 23 hours a day," Peters said. "The difference is huge. I am so thankful I did it."