Since the mid-1990s, pediatricians have urged moms, dads and caretakers to place sleeping infants on their backs to help reduce the risk of sudden infant death syndrome, or SIDs.
Cases of unexplained death have since dropped by more than half, but a far less dangerous side effect has also cropped up: A growing number of babies now have "positional plagiocephaly," or flat spots on the sides or backs of their heads.
A new study in Canada, published in the journal Pediatrics on Monday, found that more than 46 percent of 2- to 3-month-old babies may have some form of the condition, although most cases are mild.
Flat areas on the backs or sides of babies' heads are typically caused by pressure on the bones of the skull and can develop in the first few months of infants' lives. In some cases, the change in head shape is so subtle it is difficult to spot, in others it is quite clear.
"The suggestion is that there has been an increase in the development of 'positional plagiocephaly' since the 'Back to Sleep' campaigns," study author Aliyah Mawji, a researcher and registered nurse with Mount Royal University in Alberta, Canada, wrote in an email to The Huffington Post.
She warned that there is no earlier data with which to compare the new numbers. Therefore, the apparent increase in flatness of babies' heads may be due to the fact that people are generally more aware of the condition now than they were before.
The good news, experts say, is that the flat spots are generally harmless. Mawji said there is some indication that children with positional plagiocephaly have mild developmental delays, but that those typically disappear by 18 months.
"There are no functional problems that I know of, except for a distorted head," said Dr. S. Anthony Wolfe, head of plastic surgery and director of craniofacial surgery at Miami Children's Hospital, who did not work on the new study, but has reviewed it.
The condition can be treated with specialized helmets that babies wear, typically after 6 months of age, but Wolfe stressed that parents would typically only consider that option in more severe cases and for cosmetic reasons. "Some commercial makers of helmets insinuate that if you don't treat it, you may have some [jaw] dysfunction," he said. "But it's really for the head shape and the head shape only."
When it started, the primary focus of the "Back to Sleep" campaign -- now known as the "Safe to Sleep campaign" -- was to ensure babies were placed on their backs during naps and at night in order to reduce risk of SIDs. Although it made a significant dent in the number of SIDs cases, in recent years, the decline has stalled. Newer campaigns focus on a broader range of safe sleeping practices, like using a firm mattress and avoiding soft bedding in a baby's crib. Overall, SIDs is rare, affecting just over 2,200 babies per year in the United States, according to the Centers for Disease Control and Prevention.
As for flat spots, Mawji said parents can prevent them by switching the side of the head their baby puts pressure on when sleeping. The American Academy of Pediatrics also encourages parents to make sure their babies get lots of tummy time, in order to strengthen their neck and shoulder muscles, and minimize the amount of time there is pressure on their heads.
The new study looked at the rates of 440 infants at four community health clinics in Canada, but Mawji said the findings could be loosely applied to the U.S., which is more diverse in terms of culture and socioeconomics.
"My best guess is that my results -- 46.6 percent of infants aged 7 to 12 weeks -- would actually be an underestimation in some parts of the U.S," she said.
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Their Baby Cuteness Doesn't Predict Adult Attractiveness
A study published in the journal <em>Infant Behavior & Development</em> revealed that the standard "<a href="http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCQQtwIwAA&url=http%3A%2F%2Fwww.youtube.com%2Fwatch?v%3DXTV8bOv3Jhs&ei=0uLBToKrMuPu0gHkmNH0BA&usg=AFQjCNFtutJJhlTFZJ2fm-cmsDo46XMpzw" target="_hplink">You Must Have Been a Beautiful Baby</a>" has little to do with reality. When 253 college students were asked to rank photos of the same individuals as infants and young adults (without being told who was who), there was <a href="http://bodyodd.msnbc.msn.com/_news/2011/08/31/7542626-must-have-been-a-beautiful-baby-maybe-not" target="_hplink">no relationship between how cute the students found the babies and how attractive they found the grown-ups</a>.
They're Good At Sharing
No, really, it's true. It doesn't matter how many times you've heard the shout "Mine!" -- research shows babies can sense fairness at 15 months. During one study at the <a href="http://www.washington.edu/news/articles/babies-show-sense-of-fairness-altruism-as-early-as-15-months-1" target="_hplink">University of Washington</a>, 47 babies observed videos of an experimenter distributing milk and crackers to two people. When one recipient received more food than the other, the babies paid more attention. That means they had expected a fair distribution. The researchers also found that babies who did notice unfairness were more likely to share their own toys.
They Read Minds
OK, so they're not exactly psychic. But a <a href="http://www.sciencedaily.com/releases/2011/11/111101130204.htm" target="_hplink">recent study</a> from the University of Missouri found that babies just 10 months old are starting to follow the thought processes of others. Yuyan Luo, an associate professor of developmental psychology who conducted the study, tells The Huffington Post, "Babies, like adults, when they see something for the first time -- when something is surprising -- they look for a long time. It shows [they recognize] something is inconsistent." It's called the "violation of expectation," she explained. When babies are surprised by something or notice something unexpected has happened, they tend to gaze at that thing longer. In Luo's research, babies watched actors consistently choose object A (such as a block or a cylinder) over object B. When an actor then switched to object B, the babies stared for about five to six seconds longer, meaning they recognized the change in preference.
They're A Little Bit Racist
Don't judge a book by its cover. Treat all people the same. We're all equals. These are sentiments parents strive to teach their kids from a very young age. And they should. Starting, like, immediately. Researchers at the University of Sheffield in the United Kingdom found that babies at three months <a href="http://www.world-science.net/exclusives/060212_racefrm2.htm" target="_hplink">begin showing a preference for the faces of people of their own race</a>. But not all hope for equality is lost. The same study showed that babies who are exposed to people of all different races are less likely to develop bias at such an early age.
The Rhythm Is Gonna Get Them
Researchers from Brigham Young University found that five-month-old babies can <a href=" http://news.byu.edu/archive08-oct-babymusic.aspx" target="_hplink">identify an upbeat song as being different from a series of sad, slow songs</a>. In other words, they are happy. They know it. They will clap their hands. Or stare longer, as the case may be. The experimenters showed babies an emotionless face while music played. When they played a new sad song, the babies looked away. When the music pepped up, the babies stared for three to four seconds longer.
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They Can Read Lips ... Kind Of
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