Post #5 Concluding remarks on the Back-to-Sleep series

Elizabeth Fama concludes her comprehensive series with the (many) remaining questions, as well as possible detrimental effects on inequality

In Post #1, Ms. Fama introduced her critical appraisal series on the back-to-sleep recommendation. In Post #2, she explored the downsides of back sleeping. Post #3 explained the nuances of sudden infant death syndrome. Post #4 featured an evidence review.

This week, Ms Fama concludes this amazing series. JMM

I Have More Questions than Answers

How closely does the decrease in SIDS track the decrease in overall infant mortality? An interesting attempt to answer this by Goldstein et al comes up with an answer of extremely closely, although I see some problems with their methodology.

Regarding safe sleep advice, can we break out how much of the reduction in SIDS came from each directive—back sleep, not smoking, using firm mattresses, taking away blankets, bumpers, and plush toys, keeping the room cool, not sleeping the child in car seats, bouncers or strollers, etc.?

Are babies in fact crawling less, statistically, as we’ve seen anecdotally among friends and family? Does it matter?

On the costs side, how much should we care about developmental delays? I’m willing to hear that they don’t matter, given that children are individuals who develop at different rates anyway. But we should at least try to find out. How common are developmental delays beyond 18 months, and do they have repercussions later in life?

Some countries have always slept babies on the back—how have their milestones changed or not changed over time?

Do full-term infants have more quiet sleep on their tummies, as ventilated premies do? What effects, if any, does having fewer hours of quiet sleep have on growing brains?

Are parents more sleep-deprived as a result of Safe to Sleep, and what are the health consequence to children of that, for example car accidents? Are the skyrocketing rates of postpartum depression among mothers—from 9.4% in 2010 to 19.3% in 2021, a relative increase of 105%—in part due to lack of sleep, because babies are constantly semi-aroused?

How many cases of craniosynostosis are being missed because of the increase in benign positional plagiocephaly, and how many unnecessary resources are spent differentiating between the two?

How Should We Worry About Inequality?

SIDS rates are highest among poor families, people of color, single mothers, and people in disadvantaged areas. When surveyed, Black people, Native People, and Pacific Islanders report more tummy-sleeping. These disparities cause the NICHD, AAP, and CDC to pour extra resources into disseminating the Safe to Sleep message to these groups. But this ignores the higher SIDS rates among these groups before we suggested back sleep for everyone.

Moreover, these are the people more negatively affected by the costs of back sleeping. How many single mothers with multiple jobs who must rely on day care and have older children are able to do extended tummy time with their infants? Does the ratio of caregivers to babies and children in daycare allow the dedicated attention that physical therapy requires? How many disadvantaged parents can afford blackout shades, Snoos, totally quiet houses?

Given that we are concerned about disproportionately affecting high-risk groups, it’s imperative to understand how important delayed motor skills and developmental milestones are, and to tease out exactly how much of the success in lowering SIDS was truly due to supine sleep.

Conclusion

Should you put your baby to sleep on her back or her belly? I wish I could give you an answer. After my deep dive, I’ve found nothing that proved to me that tummy sleeping by itself is unsafe.

There are plausible reasons to choose back sleep. First, back sleep is likely preventing many accidental suffocations. However, this risk is greatly diminished if you have a safety-tested crib with no toys and no bedding other than a tightly fitted sheet around a firm mattress. Second, it makes sense that a small number of SIDS cases are caused by genetic mutations that are linked to cardiorespiratory or autonomic vulnerabilities and back-sleeping helps these babies by keeping them semi-aroused. The problem here is it’s nearly impossible to know whether your baby is one of those rare few, and thus your perfectly healthy infant may be sleeping chronically poorly. Third, if Paul Goldwater’s theory on bacterial-viral infections is correct, specific toxigenic bacteria on the crib sheet may more easily colonize the nose of a prone infant already ill with a virus, or the slightly increased temperature and humidity around the mucous in the nostrils may enhance the colonization and growth. But these ideas have never been fully quantified (and are a neglected area of current research), and again, there seem to be costs to sleeping a healthy, full-term infant on her back.

Ralph Pelligra and colleagues wrote in a 2005 paper—the only paper I found asking the same questions I had—that because there is no known etiology for SIDS, and no causal relationship with prone sleep, the Safe to Sleep campaign “can be viewed as a large-scale human experiment rather than a documented preventive therapy program.”

These are strong words that most physicians would argue against. I would say it differently: a lot of money and a lot of public-policy muscle has gone into a campaign that doesn’t have robust evidence. That campaign is also silent on the costs of back sleeping, and just how variable the danger of SIDS is, instead promoting an overly simplified, one-size-fits-all message. (For instance, we should be talking to parents about, and energetically trying to understand why, 20.4% of SIDS deaths happen in childcare settings.)

My wish is that parents could be armed with better research and better information about the research we have, and then be trusted to make care decisions for their families.

My granddaughter eventually learned to roll from supine to prone at eight months. By ten months, the Owlet camera showed her choosing to sleep on her tummy (her butt adorably high in the air) and—either due to age or to newfound comfort—she finally began sleeping through the night.