Why Inclined Baby Sleepers Are So Dangerous

baby in inclined sleeper
baby in inclined sleeper

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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 various studies determined that the Rock 'n Play does not, in fact, "rock"—at least not when it comes to safe sleep for infants.

An April 2019 Consumer Reports (CR) investigation indicated that dozens of infant deaths had been linked to inclined sleepers like the Rock 'n Play and similar models. In October 2019, the Consumer Product Safety Commission (CPSC) released results of its own study on the safety of inclined infant sleepers, and it issued a strong warning for parents to avoid using these products. The organization recommended that no infant sleep products with more than a 10-degree recline should be sold (sleepers typically have an incline of up to 30 degrees). They've been repeatedly linked to suffocation and sudden infant death syndrome (SIDS).

By this point, however, the market was already flooded with similar products that were just as dangerous, many of which have also been linked to infant deaths. Also, very few of the recalled products were actually accounted for years later, meaning that some consumers kept the products or disposed of them in another way.

That's partly why President Joe Biden signed the The Safe Sleep for Babies Act of 2021 (H.R. 3182) in May 2022. The bill—which was introduced in May 2021 by Sen. Tammy Duckworth (D-IL), Sen. Rob Portman (R-OH) and Sen. Richard Blumenthal (D-CT)—bans the manufacture and sale of inclined sleepers and crib bumpers.

According to the legislation, inclined sleepers are "those designed for an infant up to one year old and have an inclined sleep surface of greater than 10 degrees." Crib bumpers are defined as "padded materials inserted around the inside of a crib and intended to prevent the crib occupant from becoming trapped in any part of the crib's openings." Unpadded, mesh crib liners are not included in the ban.

"The fact that these deadly products can still be found on shelves across the country is extremely confusing to new parents who don't believe stores would be selling them if they were truly dangerous to babies," said Sen. Duckworth in an April 2021 press release about the legislation "We should be doing everything we can to help new parents and end preventable deaths like these."

The Dangers of Inclined Baby Sleepers

Fisher-Price isn't the only manufacturer who has recalled infant sleepers in recent years. For example, a company called Kids II recalled 694,000 of its Rocking Sleepers after CR linked five infant deaths to the product. Other manufacturers that have issued recalls include Graco, Summer Infant, Delta Children, and Evenflo; all of their sleepers might increase the risk of suffocation.

To understand the danger of Rock 'n Plays and similar sleepers, the CPSC commissioned a study in 2019 involving infants who were carefully monitored while using the products. Researchers first looked into whether babies move differently in the sleepers, and discovered that they were sometimes found on their tummies, which means a roll had occurred, says Erin Mannen, Ph.D, a biomechanics researcher at the University of Arkansas for Medical Sciences, and the lead researcher on the study.

"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," explains Dr. Mannen. "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."

The study also pointed out several other hazards related to the sleepers. For example, in some cases, the baby's face had come in contact with the plush sides of the product, which affected their breathing. "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," says Dr. Mannen. Also, because the products are so soft, "when babies try to move there's not a firm surface for them to push against," she adds.

Even without rolling onto their tummies, infants are at risk of positional asphyxia in inclined sleepers; that's because their heavy heads have a tendency to fall forward due to the steep angle. "We found that any angle above 10 degrees is too steep for infants, whose heads are disproportionately heavy," says Dr. Mannen. Also, 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.

Safe Sleeping Guidelines for Babies

The best way to protect your sleeping baby is following the latest guidance from the AAP. Babies should always sleep on their backs on a firm, flat surface with nothing else except a tight-fitting sheet, says Steven A. Shapiro, D.O., chair of the Pediatrics Department at Abington–Jefferson Health. Infants sleepers don't follow these guidelines; they're an inclined, curved sling with plenty of soft padding

Given the new legislation, parents should avoid inclined sleepers—even ones found in secondhand shops or daycare centers—because these products aren't safe for sleep. Remember that infants should always sleep alone, on their backs, in an empty crib or bassinet. Parents are also encouraged take caution when allowing infants to sleep in any product not recommended for this purpose, including loungers, pillows, and positioners.

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 specifically. 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.