NannyCare Mattress and Owlet Connected Sock: Are These Sudden Infant Death Syndrome Prevention Devices Really Useful?

In recent years, baby product shelves ,and even more so parenting forums, have filled with devices promising to monitor a newborn's breathing during sleep and to prevent what is still commonly called sudden infant death syndrome (SIDS), now renamed sudden unexpected infant death (SUID) in many countries.

Two categories of products exist:

respiratory movement detection mattresses (of which the NannyCare is the most visible representative in France)
connected oximetric socks (primarily the Owlet Dream Sock).

These devices sell for several hundred euros, backed by powerful commercial arguments and fear-based marketing. They are now present in many households, and sometimes recommended by healthcare professionals, including in nurseries and by childminders.

Yet the available evidence to date calls for a considerably more critical look at these products. This article offers an analysis of their actual utility, their documented limitations, and the collateral risks that manufacturers rarely highlight.

What These Devices Are

The NannyCare: A Movement Detector, Not a SIDS Preventer

The NannyCare is a pressure-sensor mattress placed under the infant's mattress. It detects micro-movements and respiratory movements of the chest. In the absence of detected movement for 20 seconds, or if the respiratory rate falls below 8 cycles per minute, an audible alarm is triggered. The manufacturer presents it as a "Class IIB CE-certified medical device" and claims that its effectiveness is "medically recognised".

CE Class IIB certification attests to compliance with European regulatory requirements for device safety, but in no way validates the clinical efficacy of the device in reducing the risk of SUID.
The detection of mechanical micro-movements cannot distinguish an obstructive apnoea from a central apnoea, nor can it detect cardiac events. The device responds to an absence of movement, not to hypoxaemia or a confirmed cardiorespiratory arrest.

This device requires the infant's bed to be at least 50 cm away from the parents' bed, meaning parents must get up to pick up and put down the baby: an open sidecar cot (co-sleeping bedside crib) will not be compatible.

The Owlet Sock: A Connected Pulse Oximeter, Outside a Medical Context

The Owlet Dream Sock (or Smart Sock in its earlier versions) uses photoplethysmography (the principle of pulse oximetry) to measure oxygen saturation and heart rate via the blood vessels of the infant's foot. This data is transmitted to a smartphone app and an alert is triggered if the values fall outside predefined ranges.

The regulatory trajectory of this product is as follows: In October 2021, the FDA notified Owlet Baby Care that the Smart Sock was being marketed without market authorisation, in violation of the Federal Food, Drug, and Cosmetic Act, forcing the product's withdrawal from the US market.

Owlet then ceased sales and announced a resumption after obtaining regulatory authorisation. A later version, the Dream Sock, subsequently obtained FDA market clearance, not as a SUID prevention device, but as a vital signs monitoring tool for healthy infants. The manufacturer itself states in its terms of use that the Dream Sock is not intended to diagnose, treat or prevent sudden infant death syndrome.

What the Experts Say

The American Academy of Pediatrics: No Evidence of Efficacy for Healthy Infants

In its 2022 recommendations on sleep-related infant deaths, the American Academy of Pediatrics (AAP) explicitly recommends against using home cardiorespiratory monitors as a strategy for reducing the risk of SUID, noting that their use has not been documented as reducing the incidence of SIDS. This is a Level A recommendation — that is, based on good-quality, consistent evidence oriented towards patient outcomes.

The authors found no evidence of reduced mortality through the use of monitoring.

The 2022 update to AAP recommendations also highlights that the use of these monitors risks generating a false sense of security and a reduction in adherence to official safe sleep recommendations — the only measures whose effectiveness is genuinely demonstrated.

James McKenna, in his book Safe Sleep, also recommends avoiding these devices.

Collateral Risks

False Alarms: A Documented and Underestimated Problem

The majority of consumer-grade devices designed to monitor infant breathing are not subject to the same regulatory standards as medical care equipment. Many sensors regularly generate false alerts, worsening parental anxiety and depressive symptoms while negatively impacting parents' sleep.

False Security: A Paradoxical Risk for Prevention

This is one of the most serious concerns raised by professional societies. The AAP clearly expresses the fear that the use of home cardiorespiratory monitors may lead to a reduction in adherence to safe sleep recommendations.

A parent who trusts a monitoring device may be less rigorous in following sleep safety guidelines — the only measures whose effectiveness is genuinely demonstrated.

The Exploitation of Grief and the Rhetoric of Testimonials

Manufacturers' communications rely heavily on testimonials from parents who have experienced dramatic situations. While this approach is humanly understandable in its foundation, it exploits the emotional vulnerability of parents and creates an implicit pressure that clouds judgement. It is important to emphasise, in this context, that no reduction in sudden unexpected infant death mortality has been observed with these devices in any study to date.

For Whom Might These Devices Be Useful?

Home apnoea monitors may have value for certain infants at risk of apnoea or cardiovascular events after hospitalisation, but should not be used routinely. The indications recognised by the AAP remain narrow: premature infants with recurrent prolonged apnoea, infants on home oxygen, infants with neurological or metabolic disorders affecting respiratory control, or anatomical airway abnormalities. In these situations, prescription must be medical, the device must be an approved medical device, and monitoring must be structured.

For a healthy, full-term infant with no particular history, none of these devices provides any demonstrated clinical benefit.

What Actually Works for sudden infant death syndrome : Safe Sleep Recommendations

The "Back to Sleep" campaign led to a considerable reduction in the incidence of SIDS in France since the 1990s.

Prevention recommendations are based on environmental measures with documented effectiveness: systematic supine positioning for every sleep and by every carer, firm and flat sleeping surface sized to the cot, absence of soft bedding (pillows, duvets, blankets, wedge positioners, bumpers), moderate room temperature (18–20°C), room-sharing without bed-sharing for the first six months, avoidance of active and passive smoking, and breastfeeding.

For breastfeeding mothers, for whom night feeds contribute to lactation, "breastsleeping" is often more restful. International recommendations exist for the safety of bed-sharing (co-sleeping): these are discussed in a dedicated article.

Conclusion

The infant monitoring device market is estimated at several billion dollars worldwide. It feeds on a legitimate fear but markets responses that do not reflect the available scientific evidence. The sleep environment remains the only prevention lever whose effectiveness has been established.

Interested in this topic? We address the themes of infant sleep and SUID prevention in our training programmes.

References

Moon RY, Carlin RF, Hand I; AAP Task Force on Sudden Infant Death Syndrome and the Committee on Fetus and Newborn. Sleep-Related Infant Deaths: Updated 2022 Recommendations for Reducing Infant Deaths in the Sleep Environment. Pediatrics. 2022 Jul 1;150(1):e2022057990. doi: 10.1542/peds.2022-057990. PMID: 35726558.
Moon RY, Carlin RF, Hand I; AAP Task Force on Sudden Infant Death Syndrome and the Committee on Fetus and Newborn. Evidence Base for 2022 Updated Recommendations for a Safe Infant Sleeping Environment to Reduce the Risk of Sleep-Related Infant Deaths. Pediatrics. 2022 Jul 1;150(1):e2022057991. doi: 10.1542/peds.2022-057991. PMID: 35921639.
Ramanathan R, Corwin MJ, Hunt CE, Lister G, Tinsley LR, Baird T, et al.; Collaborative Home Infant Monitoring Evaluation (CHIME) Study Group. Cardiorespiratory events recorded on home monitors: comparison of healthy infants with those at increased risk for SIDS. JAMA. 2001 May 2;285(17):2199-207. doi: 10.1001/jama.285.17.2199. PMID: 11325321.
Sodini C, Paglialonga L, Antoniol G, Esposito S. Home Cardiorespiratory Monitoring in Infants at Risk for Sudden Infant Death Syndrome (SIDS), Apparent Life-Threatening Event (ALTE) or Brief Resolved Unexplained Event (BRUE). Life (Basel). 2022 Jun 13;12(6):883. doi: 10.3390/life12060883. PMC: PMC9227273.
U.S. Food and Drug Administration. Warning Letter to Owlet Baby Care, Inc. Re: Smart Sock Baby Monitor. Silver Spring (MD): FDA; 2021 Oct 1. Available at: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/owlet-baby-care-inc-613499-10012021.
Strehle EM, Gray WK, Gopisetti S, et al. Can home monitoring reduce mortality in infants at increased risk of sudden infant death syndrome? A systematic review. Acta Paediatrica. 2012 Jan;101(1):8-13. PMID: 21919983.
Tieder JS, Bonkowsky JL, Etzel RA, et al.; Subcommittee on Apparent Life-Threatening Events. Brief Resolved Unexplained Events (Formerly Apparent Life-Threatening Events) and Evaluation of Lower-Risk Infants. Pediatrics. 2016 May;137(5):e20160590. doi: 10.1542/peds.2016-0590. PMID: 27244835.
Cribs for Kids. Updated American Academy of Pediatrics 2022 Recommendations on Safe Sleep. Pittsburgh (PA): Cribs for Kids; 2022 Jul. Available at: https://cribsforkids.org/aap-recommendations-2022/.