Happiest Baby is proud to announce that SNOO is the first—and only—medical device to receive De Novo authorization from the Food and Drug Administration (FDA) for its ability to keep sleeping babies safely on their backs.
“As a pediatrician for over 40 years, I’ve witnessed far too many times the unbearable pain of parents whose placed their baby in bed at night…only to find them lifeless in the morning,” said Dr. Harvey Karp, co-founder and CEO of Happiest Baby, Inc. “Stomach sleeping leads to the tragic death of thousands of healthy infants every year. Yet, we routinely put babies in bed—totally unsecured—for 12-14 hours every day. Just as infant seats dramatically improve car safety, we hope to dramatically improve sleep safety by keeping babies on the back and reducing risky rolling.”
Below are the details about SNOO’s FDA De Novo authorization, and for more information, read the full press release here.
Indications for Use
The SNOO Smart Sleeper bassinet plus the SNOO Sleep Sack are jointly intended to facilitate a supine position during sleep. Infants who are placed in a supine sleep position are at a lower risk of SIDS/SUID. The device is intended for home use by caregivers of infants from birth to 6 months of age, who are not yet able to roll over consistently.
Note Regarding Indications for Use:
The American Academy of Pediatrics states that babies should be placed on their “[b]ack to sleep for every sleep. To reduce the risk of sleep-related death, it is recommended that infants be placed for sleep in a supine (back) position for every sleep by every caregiver until the child reaches 1 year of age. Side sleeping is not safe and is not advised.”1 The National Institute of Child Health and Human Development also states that caregivers should “place all babies—including those born preterm and those with reflux—on their backs to sleep until they are 1 year old.”2
The SNOO is demonstrated to facilitate a supine position during sleep; however, the SNOO has not directly demonstrated a reduction in the incidence of SIDS/SUID.
This device is indicated for use in infants from birth to 6 months of age, until babies can roll over consistently. “Roll over consistently” means the baby has demonstrated—on multiple occasions—the ability to roll from stomach to back during sleep. Parents should be advised that prone (stomach) sleeping is never safe when a baby is swaddled or in the presence of soft bedding or toys in the sleep environment.
1 Moon, R. Y., Carlin, R. F., Hand, I. (2022, June 21). Sleep-related infant deaths: Updated 2022 recommendations for reducing infant deaths in the sleep environment. American Academy of Pediatrics. Pediatrics (2022) 150(1)
DO NOT USE this product if the infant can push up on hands and knees, or has reached 6 months of age, whichever comes first.
DO NOT USE this product if the infant has any condition that would prevent placement in the supine position.
Note: If your baby has a medical condition and you have questions about whether the back sleeping position and/or SNOO are appropriate, please contact your child’s health care provider prior to use.
FAILURE TO FOLLOW THESE WARNINGS AND INSTRUCTIONS COULD RESULT IN SERIOUS INJURY OR DEATH. READ ALL INSTRUCTIONS BEFORE ASSEMBLY AND USE OF THE PRODUCT. ADULT ASSEMBLY REQUIRED. DO NOT USE THIS DEVICE IF IT IS DAMAGED OR BROKEN.
THE SNOO IS DEMONSTRATED TO FACILITATE A SUPINE POSITION DURING SLEEP; HOWEVER, THE SNOO HAS NOT DIRECTLY DEMONSTRATED A REDUCTION IN THE INCIDENCE OF SIDS/SUID.
THIS DEVICE IS ONLY INDICATED FOR USE WITH INFANTS WHO CANNOT CONSISTENTLY ROLL OVER.
Prevent Fall Hazards
- To help prevent falls, DO NOT USE this product if the infant can push up on hands and knees, or has reached 6 months of age, whichever comes first.
- Maximum weight: 25 lb (11.3 kg).
Prevent Strangulation Hazards
- When using the SNOO Sleep Sack, ALWAYS have the zipper fully closed – at top and bottom—and make sure the soft protective zipper hood is in place.
- ALWAYS keep SNOO on a flat, even surface.
- NEVER place anything under the SNOO legs or mattress to elevate the baby’s head, other than products authorized by Happiest Baby.
- Strings can cause strangulation. Do not place SNOO’s protective cloth bag or other items with a string in SNOO.
- DO NOT suspend strings or unapproved mobiles over SNOO or attach strings or toys.
- DO NOT place SNOO near a window or patio door where cords from blinds or drapes can strangle an infant.
- Keep the power adapter cord out of reach of infants and children.
Prevent Suffocation Hazards
- To reduce the risk of SIDS, infants should only be placed on the back to sleep, unless otherwise advised by their physician.
- Infants have suffocated:
- In gaps between extra padding and the side of a bassinet/cradle, and
- On soft bedding.
- ONLY place your baby in SNOO in a Happiest Baby approved SNOO Sleep Sack, that is fully closed—at top and bottom—and properly attached to the safety clips – and make sure the soft protective zipper hood is in place.
- Use only the mattress pad provided by Happiest Baby. NEVER add a pillow, comforter, or another mattress for padding.
- NEVER place additional object in SNOO, such as blankets, toys, or other materials.
- ALWAYS ensure the mattress pad is positioned correctly. Do not create any pockets between the mattress pad and mesh sides.
- SNOO reduces rolling when used as directed. ALWAYS secure the swaddle’s wings to the bed’s safety clips when infant is in SNOO.
- If a sheet is used with the mattress pad, use only the one provided by Happiest Baby, or an authorized Happiest Baby partner.
- NEVER use plastic bags or other plastic film as a mattress cover.
- Discard all plastic packaging materials immediately after opening.
- NEVER place more than one infant in SNOO Smart Sleeper at a time.
Prevent Injury Hazards
- NEVER place more than one infant in SNOO Smart Sleeper at a time.
- NEVER carry SNOO with an infant in it.
- Young children should not be allowed to play unsupervised in the vicinity of SNOO.
- SNOO reduces accidental falling when used as directed. ALWAYS secure the swaddle’s wings to the bed safety clips. Securing the infant will help prevent dangerous rolling and falls and reduce the risk of strangulation from the entrapment of clothing of body parts (e.g., straps, necklaces, ribbons for pacifiers).
- ALWAYS remove the baby from SNOO before lifting, tipping, or moving the bed.
- ALWAYS ensure that SNOO legs are securely inserted and screwed into the base before use.
- ALWAYS keep SNOO on a flat, even surface.
- Keep away from open fires and other sources of strong heat, such as electric heaters, gas fires, etc.
- Do not place anything inside SNOO to elevate the mattress. The American Academy of Pediatrics warns that excessive elevation may result in an infant sliding into a position that might make breathing difficult.
- All assembly fittings should always be tightened properly, and care should be taken that no screws or other small parts become loose.
- Do not use body of bassinet without its legs.
- ONLY use the mattress that comes with SNOO.
IMMEDIATELY CONTACT YOUR PHYSICIAN IF YOUR BABY IS UNUSUALLY FUSSY OR NOT RESPONDING NORMALLY.
SNOO IS NOT A SUBSTITUTE FOR RESPONSIBLE ADULT SUPERVISION.
- Continue to monitor and check in on your baby as you would normally.
- Read and follow instructions before assembly and use. If you have difficulty reading or understanding these instructions, please reach out to customer support for assistance.
- The universal standard of care is that a responsible adult should always be available and in near enough proximity to promptly respond to a baby’s needs. With the SNOO, there is no change to the standard of care expectation.
- Homes where tobacco, alcohol and drugs are used have shown an increased risk of SIDS/SUID. Consider speaking with your child’s health care provider prior to use.
- Before using, inspect SNOO for damaged hardware, loose or missing components, or sharp edges.
- NEVER use SNOO if any parts are missing or broken. Request replacement parts and instructional literature via happiestbaby.com if needed. (DO NOT substitute parts.)
- Notify your doctor if your baby develops any skin irritation from the SNOO Sleep Sack.
- Stop using SNOO when the child can sit, get on hands and knees, kneel, or pull his or her body up while in SNOO.
- For indoor use only.
- This product is not a toy. Do not allow children to play with it.
- Do not pour water or liquids into SNOO.
- Only use the power adapter provided. Use of other power adapters may permanently damage the bed.
- Keep this user guide for future reference.
- Please note that use of the device may be associated with possible exacerbation of plagiocephaly and/or gastroesophageal reflux.
Contents of SNOO Box
The SNOO Smart Sleeper includes:
- 1 SNOO
- 1 mattress
- 1 water-resistant cover
- 1 organic cotton sheet
- 3 organic cotton SNOO Sleep Sacks (S (5-12 lb / 2-5 kg) in SNOO; M (12-18 lb / 5-8 kg), and L (18-25 lb / 8-12 kg) in boxes)
- 4 legs
- 1 cable guide
- 1 power supply
The SNOO Smart Sleeper (SNOO) bassinet is a free-standing bassinet that is to only be used in combination with the SNOO Sleep Sack.
The SNOO bassinet has mesh sides, an 18 mm thick polyurethane (PU) foam mattress, and safety clips on the right and left sides of the bassinet’s platform designed to physically attach the SNOO Sleep Sack to the bassinet.
In addition, SNOO provides a gentle shushing and rocking by safely moving the baby back and forth in the horizontal plane. SNOO detects the baby’s cries and automatically responds with gradually increasing white noise and motion.
SNOO Sleep Sack
The SNOO Sleep Sack is a cotton swaddle (5% elastane) available in three sizes with fixed wings made of tightly woven, non-stretchy cotton fabric that extend to the right and left of the infant’s body. A narrow, tubular elastic loop at the end of each wing is slid onto the safety clip, thereby securing the infant – swaddled in the sleep sack – on the back during sleep. The SNOO Sleep Sack features two panels of breathable, synthetic mesh (at the shoulders and hips) to reduce the risk of overheating, another well-known cause of SUID. In addition, the secured swaddling prevents injuries and death from accidental falls out of the bassinet.
Happiest Baby App
The Happiest Baby App can be downloaded from Google Play or through an App Store. The levels of motion of the SNOO bassinet can be adjusted using the Happiest Baby App. Application features include motion limiter, level lock, starting level motion, responsiveness adjustment, sleep tracking, and weaning (to help the baby transition from SNOO to the crib). Sleep tips are also available on the application.
SNOO Smart Sleeper, including the SNOO Bassinet and the SNOO Sleep Sack, is intended for use by infants from birth to 6 months of age (weighing from 5 to 25 pounds) or until when the infant can push up on hands and knees, whichever comes first; see table below for SNOO Sleep Sack size chart.
SNOO Sleep Sack Size Chart
Baby Weight Range
52 cm x 33 cm
20.5 in x 13 in
59 cm x 33 cm
23.2 in x 13 in
64 cm x 33 cm
25.2 in x 13 in
The American Academy of Pediatrics recommends that babies should only sleep on the back for the first year of life (unless otherwise instructed by their health care provider). Swaddling reduces fussing and enhances sleep during the first 6 months of life. Parents may choose to keep both arms swaddled for sleep for that entire time, or they may release one or both arms and allow them to extend out through the arm holes. Arm release is usually done at around 3-4 months of age, which is a time when most babies have sufficient motor control to allow one or both arms extending through the arm holes of the swaddle without leading to a deterioration of sleep.
Real world evidence showed a rate of supine sleep position of approximately 98.7% in 1012 users. In addition, over 93 hours of video recordings showed all observed infants remaining in a supine position during their time in the SNOO.
The following adverse events have been reported at or below expected rates when using the SNOO Smart Sleeper: death, gastroesophageal reflux, plagiocephaly, aspiration, contusion, and dermatitis.
Instructions for Use
Putting SNOO Together
- Open the box and place your SNOO upside down on a clean floor.
- Snap each leg into the base. (Line up each red and blue arrow on the legs with a matching colored arrow on the base.)
- Screw each knob in all the way. (No need to over-tighten.)
- To detach the legs, unscrew each knob all the way, pinch the two grey clips, and pull out each leg.
Directions to Swaddle & Secure Infant in the SNOO Smart Sleeper
- On a flat surface, unzip the SNOO Sleep Sack and lay the inner bands fully open and apart.
- Lay the baby on the back, on top of the open sleep sack and bands. Note: The shoulders are to be about 2” higher than the top of the sleep sack.
- Straighten the baby’s arms, pull the inner bands around them, and secure the infant’s arms at the sides snugly with the Velcro. Note: The bottom edge of the bands should cover the wrists.
- Raise the between-the-legs flap and Velcro it to the closed inner band.
- Bring the SNOO Sleep Sack snugly over each shoulder, and zip the SNOO Sleep Sack completely closed, top and bottom. Make sure the soft protective zipper hood is in place and well below the chin.
- Lay the baby on their back upon the mattress in the SNOO bassinet.
- Slide the small loops, located at the ends of each SNOO Sleep Sack wing, over the safety clips—on the right and left side of the bassinet—to secure the swaddled baby on the back.
Optional: Once the baby has greater motor control, the sleep sack’s arm holes can be unsnapped to allow the baby’s arms to be unswaddled.
Plug SNOO into the electric outlet.
The Activity button’s white light will blink for several seconds and then turn a steady white.
Place the baby in SNOO:
- Lay the swaddled baby into the SNOO—on the back—feet at the end nearest the Activity button.
- Ensure each elastic loop—at the end of each safety wing—is fully inserted onto the safety clips (located on the right and left side of the bed) for the SNOO to function.
Note: For safety, NEVER put your baby in SNOO unless swaddled in a SNOO Sleep Sack with the zipper fully closed and the elastic loops fully inserted onto safety clips.
Turn SNOO on:
Push the Activity button. The white light will turn blue and SNOO will start gently rocking and shushing.
SNOO will gently rock and shush the baby, and it will automatically respond to the baby’s cries—moving through increasing levels of white noise and motion—to find the perfect rhythm to soothe the crying or fussing.
Note: SNOO arrives to your home preset to the “motion limiter” setting, which lets the bed respond to fussing with 2 levels of higher sound and motion. If you believe your baby would benefit from a little stronger rhythmic calming, go to the app settings page and turn off “motion limiter.”
As the bed responds, each level is shown by a new SNOO Activity button color:
Blue > Purple > Green > Yellow > Pink.
Once the child is calmed, SNOO will slowly return to the gentle blue baseline level:
If crying lasts 2-3 minutes, SNOO automatically stops and the Activity button turns red. A caregiver is expected to attend to the baby.
Note: If the Activity Button is blinking white, please check that the loops of the swaddle wings are fully attached.
Turn SNOO off:
To stop SNOO, push the Activity button once or slip a swaddle wing loop off of the safety clip. Removal of the swaddle wing loop should only be performed if the baby is to be removed immediately from the bassinet.
SNOO Sleep Sack
Swaddle made of organic cotton (5% elastane) and breathable mesh. The SNOO Sleep Sack is available in three sizes: Small (5-12 lb / 2-5 kg), Medium (12-18 lb / 5-8 kg), Large (18-25 lb / 8-12 kg).
100% organic cotton fitted sheet designed for the SNOO mattress.
Bassinet legs 7” shorter than standard legs.
If the baby’s health care provider recommends elevating the baby’s head to relieve congestion, leg lifters can be used to create a very mild (~3º) incline.
Netting that protects the baby inside the SNOO bassinet from insects, including mosquitos, flies, and spiders.
Care and Maintenance Instructions
The SNOO bassinet, sleep area and mattress should be cleaned regularly using a soft cloth with warm water and mild soap.
- For safety reasons, the SNOO mesh is not removable. However, you can easily spot clean SNOO using a soft cloth with warm water and mild soap.
- Open the vertical zipper at one end of the bed to clean between the inner and outer mesh walls. Always close zipper completely before resuming use.
- Never use bleach or abrasive cleaners.
- The mattress has a water-resistant cover to prevent stains and contamination.
- Clean mattress with a soft cloth with warm water and mild soap. Do not use harsh or abrasive cleaners and do not machine wash. Allow to dry completely before using it again.
SNOO Sleep Sacks and Sheets
- Remove the sheet from the mattress and wash it and all three (3) SNOO Sleep Sacks before use.
- The sheet and sleep sacks are machine washable. Wash in warm water with other like colors. Only use non-chlorine bleach. Tumble dry on low heat.
Storage Between Uses
- When not in use: Store in a clean, dry location. Do not store outdoors or in a damp environment.
- Clean and thoroughly dry SNOO components before storing in the provided protective cloth bag.
- Clean and thoroughly dry SNOO components once more when removing from storage and preparing for use.
12V wall plug adapter
802.111b/g/n @ 2.4 Ghz
Wireless connection with internet access
iPhone or Android with the latest official OS
Happiest Baby App
Free SNOO account
Dimensions: 32” (H) x 20” (W) x 36” (L) with legs
Weight: 38 lbs
Operating Temperature: 50° to 95° F (10° to 35° C)
Storage Temperature: -13° to 113° F (-25° to 45° C)
Operating Humidity: 0% to 90% noncondensing
CPSC (ASTM F2194)
Happiest Baby, Inc.
3115 S. La Cienega Boulevard
Los Angeles, CA 90016