After its introduction in 2009, the Fisher-Price Rock 'n Play infant sleeper quickly became a cult favorite among sleep-deprived parents. News spread about the sleeper's ability to get babies to sleep faster and longer due to its "nest-like" comfort, inclined resting position and automatic rocking feature. But in April 2019, a Consumer Reports investigation determined that the Rock 'n Play does not, in fact, "rock," at least not when it comes to safe sleep for infants.
The report indicated that dozens of infant deaths had been linked to inclined sleepers like the Rock 'n Play and similar models. As a result, Fisher-Price recalled the popular sleeper. But by then, the market was already flooded with similar products that are just as dangerous, many of which have now also been linked to infant deaths.
Last week, the Consumer Product Safety Commission released results of its own study on the safety of inclined infant sleepers, and issued its strongest warning to date for parents to avoid using these products. At the time of this writing, CPSC commissioners are hard at work on a proposal mandating that no infant sleepers with more than a 10-degree recline can be sold.
The Dangers of Inclined Baby Sleepers
To learn more about why Rock 'n Plays and similar sleepers are dangerous, we sat down with Erin Mannen, PhD, a biomechanics researcher at the University of Arkansas for Medical Sciences, and the lead researcher on the study commissioned by the CPSC.
Parents: Can you explain the findings of your study?
Mannen: When our team of engineers performed this study, we first looked into whether and why babies move differently in these products. In more than 20 of the cases, infants were found on their tummies, meaning a roll had occurred. So we decided to conduct a biomechanical study to see if there was something about the design of inclined infant sleepers that contributed to the deaths. Our findings are that once babies are in a tummy down position, they don't have the strength or energy to move to a safer position. It's a new position for them, and places higher demand on some of their muscle groups, which leads to muscle fatigue. This of course leads to suffocation.
Parents: Were there any other hazards you noticed about these types of sleepers?
Mannen: In several cases, the baby's face had come in contact with the sides of the product, and was pressed against it. We didn't study this extensively, but we did recommend follow-up studies to look at breathability of the products. The question is, was there something about the fabric that's causing carbon dioxide rebreathing, which is a huge risk factor for SIDS.
But sadly, those aren't the only hazard infants face when sleeping in an inclined infant sleeper. Even without rolling onto their tummies, infants are at risk of positional asphyxia because their heavy heads have a tendency to fall forward due to the steep angle. According to Ashanti Woods, M.D., a pediatrician with Mercy Hospital in Baltimore, a baby's airway can be occluded or blocked when their chin comes in contact with their chest due to gravity. This positioning is not conducive to oxygen flow, especially in infants.
Parents: Tell us about some of the main design flaws in these products.
Mannen: There are three main problems present on most inclined infant sleepers that work in combination: first, the angle of sleep is too high. We found that any angle above 10 degrees is too steep for infants, whose heads are disproportionately heavy. Secondly, the plushness of some of the products' design aspects is a suffocation hazard; even those with the breathable mesh sides. Finally, many of these products aren't as firm as crib mattresses, so when babies try to move there's not a firm surface for them to push against.
Safe Sleeping Guidelines
In light of this alarming news, it's a good time for a quick refresher on the latest safe sleeping guidelines set forth by the American Academy of Pediatrics. While the exact guidelines do change from time to time, the AAP has stated for at least a decade that the safest sleep position for infants is on their backs.
Indeed, Dr. Woods says, "the American Academy of Pediatrics states that the safest sleeping position for an infant is flat, alone, on its back, in a crib (or bassinet, or pack 'n play) in a non-smoking environment."
When it comes to terminology, Mannen notes that an inclined sleeper is defined as a product with a 10-30 degree incline, and there are different sets of requirements as defined by ASTM (American Society for Testing and Materials) for bassinets and seats. Parents are encouraged to use all different categories of baby gear correctly and to take caution when it comes to allowing infants to sleep in a product not recommended for sleep. For example, many inclined infant seats, swings, and bouncers abide by safety guidelines and standards and include warning labels that do not recommend sleep, nor are they marketed as sleepers.
What to Do With Inclined Sleepers
Now that we know not to use inclined infant sleepers, what should you do if you've got one in your home? First things first—stop using it immediately. Don't let your little one take even one more nap in an unsafe sleeping environment. The good news is, you may be eligible for a refund. Here are the instructions to return your Rock 'n Play and here are the instructions for the Kids II sleeper. If you're not eligible, it's best to simply throw your sleeper away, unfortunately. Though it may be tempting to make a few bucks from it, it's not ethical to sell, consign or donate it.
Tips for Baby Sleep from Dr. Karp
One study reports that as many as 50% of parents in the US are not following safe sleep guidelines for infants—and while that statistic may seem shocking, it's all too understandable for sleep-starved parents.
Dr. Harvey Karp, author of the best-selling book Happiest Baby on the Block, has made infant sleep his life's work. He knows all too well the struggles parents face.
"Parents don't disregard safe sleep recommendations on purpose. Now more than ever, parents are just exhausted. We expect parents to do it all… without support. So night after night, the sleeplessness accumulates. As a result, parents either fall asleep by accident in an unsafe place like the rocking chair or sofa, or out of desperation they put baby to bed in an unsafe way because it's the only thing that helps."
Admittedly, it can be super tough to get baby to sleep alone, on his back on a firm surface. "If I told you to sleep on the floor, without a mattress, pillow, or blanket, you probably wouldn't sleep very well, either," Karp says. But there are some things you can do to make it easier: