MimoIn a recent perspective piece published in the British Medical Journal, pediatrician Dr. David King argues that expensive wearable monitors designed for babies are implying benefits that they can’t back up.

A recent CNN Money piece, boldly titled “Connected babies = more sleep for you,” highlights the buzz surrounding these devices. In it, they describe the $199 high-tech, Bluetooth-connected Mimo onesie from Rest Devices that monitors breathing, body movements, and sleep. According to Rest co-founder Dulcie Madden, Mimo gives parents peace of mind about their baby.

There are a number of other devices on the market that offer similar functionality, like Owlet’s smart sock, which will cost $250, or Sproutling’s baby band, which is currently sold out. Owlet describes its value to parents this way,

At Owlet, we are focusing on what matters most to you. We have spent thousands of hours honing our algorithms and utilizing the most advanced health monitoring technology so that you can have one less thing to worry about.

And according to Sproutling,

Get notified [by Sproutling] if something out of the ordinary happens. If there’s a significant change in your baby’s heart rate or skin temperature, or if your newborn rolls over while sleeping, you’ll be alerted immediately.


None of these devices makes specific claims about specific outcomes like a reduction in sudden infant death syndrome. That is left to parents to infer from the descriptions of these devices, like those above, that frame them as constantly on watch for concerning changes in breathing, heart rate, and so on.

Dr. King points out that there is no published data that suggests any benefit in any metric from these devices. He also recalls that using apnea monitors to prevent SIDS was the rage about twenty years ago – until studies showed no benefit and professional bodies like the American Academy of Pediatrics recommended against home cardiorespiratory monitoring.

I can certainly empathize with parents who buy these devices; intuitively, it seems like monitoring my child more closely must be a good thing. Frankly, as I reviewed these devices, I found myself on the fence about whether the parent side of me would buy one of these devices. Anything that could help me keep my child safe seems like a no brainer.

The physician side of me, on the other hand, is less conflicted – I wouldn’t recommend them to a parent. That said, if a parent came to me asking about this device, we’d have a discussion – I don’t think the risks are high enough where I’d outright recommend against it.

There are several points I’d highlight in that conversation. While some aspects of these monitors (like for sleep training) seem fairly benign and potentially helpful, I’m concerned about the continuous monitoring of heart rate, respiratory rate, and temperature. In an ABC News article on Owlet, Dr. Chris Retajczyk, a California neonatologist, expresses that concern like this:

For example, heart rate. There’s a huge variation in newborns, from slow heart rate to very high heart rate,” says Retajczyk. “So if the parents sees these trends, does that become worrisome when in reality it’s quite normal?

I’d also caution parents that there’s no data to support claims that these devices will really sound an alarm if something bad is about to happen. And there’s the risk that these devices will provide false reassurance when a child is actually sick, preventing a call to the pediatrician that a parent may otherwise have made.

Then there’s the issue of what to do with the data being captured. Unlike say a blood pressure monitor in a hypertensive adult or an AliveCor in someone with palpitations, these devices are capturing a lot of physiologic data in healthy infants. While use of activity tracking in sleep training (the most commonly cited use case) at least seems intuitively plausible to me, a lot of the other data is information we just don’t know how to use in this context (continuous monitoring of healthy infants) and could expose kids to unneeded downstream testing.

That said, I’m encouraged that at least one of these companies is pursuing clinical evaluation . While we contacted all three companies, Owlet is the only one that responded. They described two specific, very interesting studies underway:

  • Seattle Children’s: Evaluating device in children with congenital heart disease, specifically monitoring kids in the period between staged corrective surgeries in mortality risks are particularly high.
  • University of Arizona: Prospective study comparing frequency of desaturation events in healthy infants, preterm infants, infants with Down’s Syndrome, and infants at risk for autism

Owlet should be commended for supporting clinical testing of their devices – these kinds of studies will help physicians figure out how to guide parents in effective use of these devices. That commitment should be something we highlight to set them apart in what will surely be a crowded space. And their findings could very well change the discussion I have with parents about these devices.

At the end of the day, its up to individual parents to make a decision as to whether they think these devices will be helpful or harmful for their own children. But hopefully their pediatricians and family physicians will be important advisors, helping them understand these issues so they can make informed decisions.