Many parents consider movement monitors to help provide peace of mind while baby sleeps so they themselves can get a better night's sleep. In essence, this is all to assuage fears of Sudden Infant Death Syndrome (SIDS). Movement monitors track baby's breathing movements either through sensor pads underneath baby's mattress or via a wearable device. In the case of the Owlet Smart Sock 2, the device actually continuously tracks baby's heart rate and oxygen levels. While movement monitors don't claim to prevent SIDS, a reliable monitor may provide peace of mind. That said, safe sleep guidelines should always be followed with EVERY sleep to help reduce the risk of SIDS. Like the AAP (American Academy of Pediatrics), we urge parents to always put the baby on their back to sleep, on their own firm sleep space such as a crib, bassinet, or travel crib with a tight-fitting sheet and nothing else. That said, in the event that you are considering a movement monitor, we share the top options to consider in addition to very important buying advice.
The Best Movement Monitor Review
In order to confirm testing on EMF we performed for this review we purchased an additional EMF reader and performed additional testing on three different Owlet monitors (two v2 Socks and one v1 sock) using two different readers. We have updated this review to include this new information. As a result of this testing, we still feel the Owlet Smart Sock v2 is not a good choice based on what we feel is excessive EMF emitting from the sock. Read more below.
The Babysense 7 is a sensor pad monitor that goes under the crib mattress. It is easy to use and works well right out of the box with only a little bit of preparation. This monitor has a simple control unit you place on the front of the crib that receives data from the two pads and sounds the alarm (with red lights) if your little one stops moving for a prescribed period. The Babysense 7 is a reliable monitor with few false alarms that runs on AA batteries to limit the involvement of potentially dangerous cords. Also, it works almost as well once your little one becomes mobile (up to one years old), unlike the wearable options that start to have an increase in false alarms as baby moves more.
Like other mattress sensor pad options, the Babysense 7 requires a hard surface under the mattress to work correctly, and it is the second most expensive option in the review. It also isn't a good choice if you want a parent device to avoid alarms in your child's space. However, it is an easy to use monitor that works well for a longer period than most of the competition. We think most families will appreciate what it has to offer and can always add a video or sound option to make it more versatile.
Read Review: Babysense 7
The Snuza Hero SE is a clip style wearable with a unique vibration feature designed to rouse baby from a deep sleep gently, so they move enough (theoretically breathing) to stop the alarm. This monitor is the only option we reviewed designed with this rousing in mind. We like the simplicity of this option and the ability to use it while traveling as it doesn't require any special bedding features like the sensor mattress pads.
This clip style can be uncomfortable for some babies, and it doesn't work well if your baby can roll over or crawl as the sensor can dislodge or lose contact with the baby. This option also has no parent unit, so if the vibration doesn't rouse baby, then an alarm will go off on the diaper, and you'll need to be close enough to hear it. If you don't hear the signal, it will continue to alert which can be upsetting for infants. Some parents found the limited battery life of this unit frustrating, while others experienced some false alarms when the clip lost contact with the baby's belly. However, if you travel frequently or want a monitor that stimulates baby into movement, then the Snuza Hero is an excellent choice, and the only option we know of that has the vibration feature.
Read Review: Snuza Hero
The Angelcare AC403 is is a movement and sound monitor, something no other option in this roundup can claim. We like that this sensor pad device is reliable, has good range, and useful sound monitoring. This product works well, has a wallet-friendly price, and comes with a dedicated parent unit with a battery backup for transportability around the house. This monitor has movement sensitivity adjustability which helps limit false alarms by finding a setting ideal for your situation.
Be sure to route all cords out of the reach of the baby to avoid potential injury or death related to strangulation. Even if you believe your baby cannot roll/move or come into contact with nearby cords, it is vital to install your monitor safely the first time to avoid potential future problems.
While there is much to like about the AC403, it isn't the best for travel, and the sensor pad requires a hard surface. So, you may need to make some modifications to your crib, and hotel cribs may not be compatible. Also, it doesn't work with memory foam or hollow core mattresses, something you'll need to consider when you purchase a mattress. Angelcare does offer the Angelcare Wooden Board for Monitors accessory, for use with its movement monitors to easily and economically solve this hard surface problem. Also, user report that the sound monitoring is subpar and has annoying white noise or is too quiet to hear little ones crying. The major downside is this unit only has one sensor pad, and you can't buy an additional one. One pad instead of two means its potential use time is less as it won't work well when little ones start to roll away from the pad. However, this unit is reliable with the benefit of sound monitoring, adjustability, and included parent device and you can continue to use the sound monitor alone after your baby outgrows the movement component.
Read Review: Angelcare AC403
The Snuza Go is a budget-friendly wearable that clips to the front of your baby's diaper with a flexible sensor that rests on the infant's abdomen. It is easy to use and travels well for parents who want to monitor baby's sleep while away from home. This unit has a simple design that requires no initial setup or crib modification, giving parents that straight out of the box satisfaction you can't find in the mattress sensors. This option is similar to the Snuza Hero, but it lacks the stimulation feature designed to rouse the baby more peacefully.
The Go doesn't have a parent unit, and the loud nursery alarm can cause unnecessary upset for the baby if you don't hear it. Some parents remark that the battery life is limited, and replacements are difficult to find, but the lower price of the Go could offset this potential problem if budget is a concern. The Go isn't a great choice for older babies who can roll over or crawl, as this can lead to false alarms, and the design means it has a limited lifespan, unlike mattress sensors. Overall, this unit has a reasonable price for a simple product that works well for younger infants while traveling.
Read Review: Snuza Go
The Monbaby Smart Button is a unique wearable button that attaches to baby clothes. The button is small, portable, and more comfortable than the wearable products that clip to baby's diaper. We like the reasonable price (comparatively) and the smartphone capabilities that provides a lot of information. This Wi-Fi capable device means you don't need to stay close to the baby's location to hear the nursery alarm.
This product requires access to Wi-Fi, and some users feel that the app is challenging to use. The button itself is useless if you lose it or accidentally run it through the washer and dryer, which is something a sleep-deprived parent could easily do. However, if you make removing the button a habit, and you figure out the app's user interface, then the Monbaby is a high tech choice that keeps you informed without disturbing your baby.
To provide accurate information so that you can make the best choice for your infant, we think it is equally important to discuss the products we don't recommend, especially if we believe there is a potential health concern behind our decision.
Not Recommended Due to High EMF
Owlet Smart Sock 2
The Owlet Smart Sock 2 functions just like a pulse oximeter. The sock is worn on a baby's foot and continuously monitors their oxygen saturation and heart rate. This "sock" monitor connects to a base that communicates with an app on your smartphone and keeps you connected to your baby with alerts on your phone. This monitor collects and tracks data and prevents waking the baby with a false alarm in the nursery. It is important that parents understand that the Owlet is not a movement monitor and only tracks oxygen saturation and heart rate, not whether or not your baby is moving in a way that indicates breathing. Also, the Owlet is not a medical device and should not be used to treat, monitor, diagnose, or prevent any medical problems. However, you can use your HSA or FSA pre-tax health saving accounts to purchase this monitor.
While the concept is cool and the technology intriguing, the Owlet Smart Sock 2 is a product we do not recommend as a result of disappointing Electromagnetic Field (EMF) test results that are far higher (8 V/m) than the competition and everyday products like personal fitness monitors. In our opinion, the EMF levels from the Owlet are just too high (for more information on EMF and our testing, please see the EMF section below.) While each parent must weigh the pros and cons to make the right decision for their baby, we believe the unnecessary and uncertain potential risks related to high EMF exposure is reason enough not to use the Smart Sock on your baby. In our opinion, this is a classic instance of implementing the precautionary principle.
Also, the Owlet is expensive with a price that is more than three times some of the competition, and although they offer financing options, it is still expensive for a product with inherent problems (i.e., false alarms if the sock falls off and a sock-based system that is unusable once baby outgrows the sock). Nonetheless, the Owlet's tech gadgetry will intrigue and potentially addict many, but we worry parents will consider it a medical device when even the company says it isn't. And, it certainly shouldn't be used to replace safe sleep practices. While we think this kind of gadgetry is very cool and intriguing for the unique information it can provide to parents, until the levels of EMF are lowered it isn't a product we feel we can recommend based on our EMF test results.
The Owlet is different than the other products in this review. This monitor doesn't track movement like the other products but instead keeps track of blood oxygen saturation and heart rate, which makes it seem like something your pediatrician might prescribe for a sick child. However, Owlet and the FDA stress that this monitor is not a medical device and it is not intended to diagnose, treat, prevent, or monitor any medical problem. No monitor, including this one, should be used in place of basic safe sleeping practices like putting your baby on their back to sleep on a firm mattress, using only a tight-fitting sheet with nothing else in the sleeping area.
Movement Monitor Buying Advice
Movement monitors are considered an essential tool by some parents who hope to protect their infant from the dangers of sleep-related death. No parent is immune to the fear of SIDS, and we understand this. Even though movement detecting monitors are not approved or endorsed by the FDA or the American Academy of Pediatrics (AAP), many parents consider investing in such a product, if there's even a small chance that it can potentially save their child. While these units are not medical equipment, nor have they been proven to save lives, they may provide the peace of mind that parents desire. You can see your baby with a video monitor, and hear them on a sound monitor, but how do you know they are still breathing? Many parents have spent more than a few minutes staring at a video monitor looking for any indication of movement to put their mind at ease. You could go in the room and check, but we're pretty sure no one wants to wake a sleeping baby or cross the house in the middle of the night if they don't have to.
For great tips on SIDs prevention and the safest sleep practices for baby, read our article on how to protect your baby written by our founder and pediatrician, Dr. Juliet Spurrier. These best sleep practices are considered the ideal way to help prevent sleep-related injuries or death and are far more important than choosing the best monitor.
Types of Movement Monitors
There are two basic categories of movement monitors that work on similar principles of monitoring movement while your baby sleeps. One style is placed under the baby's mattress (above left), while the other is something they wear (above right). There are pluses and minuses to both and finding the right one for you will depend on your goals.
The most reliable options utilize sensors pads under the crib mattress. These units are designed to sense the slightest movement, like breathing, and if movement stops an alarm sounds on the nursery unit or parent device depending on the model. This type of monitor is best for at home use as it requires a hard surface under the mattress to function correctly and it continues to work well after little ones can roll or crawl. These sensor pads aren't compatible with memory foam mattresses and most travel or hotel cribs. The Anglecare AC403 and the Babysense 7 are both sensor pad monitors.
Wearables can clip onto the baby's diaper, attach to their clothing, or go on the foot. Depending on the model, they can be as small as a button or as large as an old-fashioned beeper. Wearables have more false alarms than sensor pads because it is easy for the device to lose contact with the baby. However, wearables may be ideal for travel, as they are small and don't require special mattress arrangments, but they aren't as reliable as the sensor pads, and they can fail or have false alarms. They can also be challenging to attach to clothing if your baby is already sleeping or they can become dislodged if the baby is awake.
These units do not function properly in a moving car or stroller as they are unable to determine if the movement is the baby or related to the movement of the vehicle or stroller. This inability is not a fault of any individual monitor but a result of the technology used and how it determines baby's movements.
Having a parent unit means you can move further from the baby and still hear the alarm or receive the alert. Some monitors are compatible with smartphones and send an alert to your phone via an app. However, many monitor alarms are on the sensor itself or the nursery unit. Purchasing a product without a parent unit means you need to stay within hearing distance of the alarm or you may miss it. Some parent devices can be programmed to only alert the parents instead of sounding in the nursery. This feature can be useful if your device is prone to false alarms. That way, the baby can continue to sleep peacefully unaware. Combining the movement monitor with a sound monitor can mitigate some of these problems and choosing two monitors is a popular solution for many parents, but it can be more expensive to buy and maintain two monitors. The Angelcare AC403 comes with a parent unit (or two) that doubles as a sound monitor which solves the problem of alarms in the nursery and being able to hear your baby when they cry.
False alarms can be a frightening experience (for parents and baby), and they often result in more questions than answers. Their occurrence makes reliability an important consideration and the one thing most parents complain about. In our experience, the sensor pads are the most reliable because there is no risk that the sensor will move or become dislodged. Products like the Angelcare AC403 and the Babysense 7 had fewer false alarms than the wearable products. The primary cause of false alarms seems to happen when wearable monitors lose contact with the baby's body and are no longer able to sense movement. Contact loss can happen if the sock with Owlet Smart Sock 2 falls off, the button on the Monbaby Smart Button loses contact with baby, or the Snuza products shift away from the baby's belly. As your baby becomes mobile, there is a chance of a wearable product losing contact with the baby. For this reason, the sensor pads result in fewer false alarms as they encompass a wide area of the mattress and are not dependant on a calm and stationary baby. Also, the Angelcare AC403 has a sensitivity adjustment on the nursery unit that can be altered to suit the specific needs of your nursery and child, thereby decreasing potential false alarms.
Ease of Use
Parents should consider how difficult a monitor is to use including the setup, buttons, settings, smartphone interface, and battery changes. The Babysense 7 and the Angelcare AC403 are both straightforward to turn on, but they have some adjustment settings to manage at least once. The AC403 specifically can be challenging during the initial setup. Alternatively, the Snuza Go and Snuza Hero require less initial preparation but can be frustrating to attach to a squirmy or sleeping baby resulting in false alarms or sleep disruption. Parents also complain that the battery compartment is hard to open making battery changes a dreaded chore. The Monbaby Smart Button and the Owlet Smart Sock 2 can also be difficult to attach, and the sensor and smartphone can fail to connect making the monitor nothing more than an expensive, useless accessory.
Most of the monitors in this review alert inside the nursery, so they need to be loud enough to wake you from a dead sleep in a different room. This nursery alarm should wake a baby from a deep sleep, who is theoretically not breathing, without the potential delay from a slow waking parent running to the nursery. However, this also means the alarm can potentially scare your little one which will lead to crying as opposed to gentle stimulation to encourage movement or breathing. Also, depending on the size of your house, where the nursery is in relation to your bedroom, and whether or not the monitor has become covered, the alarm could be difficult to hear. Given these variables, we highly recommend that the monitors without parent units be paired with a sound monitor. The Angelcare AC403 has a dedicated parent unit that doubles as a sound monitor, so you are sure to hear the alarm and those that work with a smartphone should be able to alert you as long as you are within range and connected, however, a delay could happen.
The Angelcare AC403 sensor pad has an adjustable sensitivity. The highly sensitive pads sensor pads on mattress style monitors can pick up ambient noise and vibration from heating vents, fans, or household appliances. If the pads pick up ambient interference, the monitor will not alarm if the infant stops moving because the sensor will think the interference is the baby. It is important to test your monitor while using everyday appliances in proximity to the baby's room (specifically fans, air filters, white noise makers, and heaters in baby's room). If the alarm does not function, then the sensor on the AC403 can be adjusted to eliminate interference. The wearable monitors are not affected by low-level ambient vibration and do not have an adjustable sensor, but don't mistake this to mean they are suitable for strollers or car seats… they are not. In fact, none of the movement monitors will work when used in a device designed to move as the monitor cannot tell the difference between a baby's movement vs. the movement of the product. If you choose the BabySense 7, you'll need to remove ambient interference from the room or away from the baby's crib.
Electromagnetic Fields (EMF)
While the jury is still officially out on the effects of EMF on the human body and the sensitive developing systems of babies, we believe there is enough evidence that indicates potential harm that parents should consider the EMF (Volts/meter) emitted by all products used close to or on their little ones. We believe that a "better safe than sorry" approach is smart and that parents should make thoughtful and informed decisions when choosing EMF emitting products. While each home already has an ambient amount of EMF and each product added to a home can up the amount of EMF exposure, putting an EMF emitting device directly on your baby is something different and we think it should be thoughtfully considered before use. With this in mind, we tested each product to determine how much EMF it emits when in use.
The Owlet Smart Sock 2 has a significantly higher level of EMF than all of the movement competition and more than any of the video monitors included in our video monitor review. Our two EMF meters registered an average of 8 V/m when placed next to the Owlet Smart Sock v2. We are not comfortable with this level of EMF right on a baby. This result is 73% that of the EMF emitted from an iPhone while making a phone call, 3x higher than a Fitbit fitness monitor (more on this below), and 12x that of the ambient EMF in our testing area!
In comparison, both Snuza models emitted no EMF over the ambient room reading (0.4 V/m). The Owlet emits almost twice as much EMF than the Monbaby Smart Button (which is also high in our opinion). The mattress sensor pads from the BabySense 7 and Angelcare AC403 emit no EMF over the ambient room in our tests. In our opinion, this means any of the movement monitors are potentially better for your baby than the Owlet Smart Sock v2, with those that emit 0 V/m over ambient being preferable.
To give you some perspective, we also tested the EMF on a smartphone in various configurations of Bluetooth, wi-fi, and calling active and not active and some wearable fitness monitors. This testing puts into perspective how the wearable monitors EMF compare to everyday items that you use or keep on your person. We feel parents can relate to this data as concerns about radiation from cell phones and cancer have increased in recent years.
A smartphone with the Wi-Fi on and making a call, measured 17 V/m at a one-inch distance, while the Owlet emitted 8 V/m at one-inch - that is 73% of the EMF emitted by the cell phone. At 1 inch away from the meter, the Fitbit has an average reading of 3 V/m which is significantly less than the Owlet Smart Sock v2 with an 8 V/m reading and the Monbaby Smart Button with a 5 V/m.
Even though there isn't conclusive data concerning what level/duration of V/m is dangerous, we would not recommend high EMF emitting products for the first formative six months (when this kind of product is useful) especially since there are good alternatives available that do not have this issue. Babies are more susceptible to EMF than adults because they are still developing and have thinner skulls. Given this information, we are disturbed that some products for baby monitoring have significantly higher EMF than the adult products we hear so much about in the media. We feel there is no real engineering reason why the Owlet Sock should have such high EMF readings when the FitBit is less than half that of the Owlet but uses similar technology transmitting similar information to your smartphone. We consider this to be a product design flaw on Owlet's part and the EMF level is just too high for our comfort.
Out of curiosity, we also measured the EMF level in an older Owlet Smart Sock v1. The EMF reading at 1-inch from the sock for the v1 is significantly lower at 1.4 V/m than the v2 sock with a reading of 8 V/m. This reading is much closer to ambient EMF levels of 0.7 V/m, which would be a more acceptable EMF level from our point of view. Our measurements of EMF in the Owlet Smart Sock v2 show that it has increased the EMF transmissions at the baby by a disturbing 5.7x higher, and at such a high level that we cannot in good conscious recommend the Owlet Smart Sock 2. We don't know why the company decided to increase the EMF level of the Bluetooth radio transmitter in the baby's sock so dramatically, but it is our opinion that placing such a high EMF source on infant babies is a disturbing engineering oversight by Owlet in the v2 design.
In our opinion, given the concerns and data to support the concept that smartphones should not be used for long periods of time next to your head because of the potential risks of radiation and cancer related to the EMF emitted by cell phones, we do NOT think it is a good idea to use an EMF emitting product directly on your baby. Especially one that emits 12 x more EMF than the ambient room levels.As such, we recommend that any EMF emitting monitors determined to be absolutely necessary be placed as far from little ones as possible for the monitor to still be functional. Given that the Owlet Smart Sock v2 must be placed directly on your baby, we feel it needs re-engineering to emit significantly less EMF (at least lower than that emitted by a FitBit) before it would be a product we'd feel comfortable recommending, despite the cool nature of the concept and the potentially useful information it can provide to parents.
Movement monitors are not a medical device, and should not be relied upon to prevent SIDS, or to monitor any medical condition. They can, however, provide some peace of mind for many parents, and if they help you get some much-needed rest, who can argue with that? No matter what your final decision on baby monitors, nothing replaces safe and smart sleeping practices to reduce the risk of SIDs. Babies should always be put to sleep on their back, in their own sleep space, with a firm sleep surface, and only a tight-fitting mattress sheet for bedding. No blankets, toys, or bumpers should be in a baby's sleep area. Creating a comfortable sleep environment can also be beneficial including adequate airflow with a fan or air filter, never smoking around your baby or in your baby's room, and keeping the room from becoming too hot with a temperature that is comfortable for an adult in lightweight clothing.
— Juliet Spurrier, MD & Wendy Schmitz