FDA issues Warning Letter to SNOO Smart Sleeper maker over unauthorized sleep sacks, hospital bundle, and quality system failures

Pediatricians and neonatal clinicians who have recommended or encountered the SNOO Smart Sleeper bassinet in home or hospital settings received a significant regulatory signal today: the FDA issued a Warning Letter to Happiest Baby, Inc., the Los Angeles–based manufacturer of the SNOO, citing a pattern of violations that includes selling unevaluated sleep sack sizes, distributing the device into hospital settings without premarket authorization, and systemic quality system failures, including reports of mold on mattresses and unsanitary conditions on refurbished units sent to customers.¹

The letter, signed June 15, 2026, and directed to Happiest Baby CEO Dr. Harvey Karp, follows an FDA inspection conducted July 21–25, 2025, at the company's Los Angeles facility.¹ "The FDA strongly cautions patients, caregivers and health care providers that the X-Small and X-Large sleep sacks, and the SNOO Hospital Bundle, have not been evaluated for safety and effectiveness by the FDA and pose increased risks," the agency stated in an accompanying public notice.

Unauthorized sleep sack sizes: X-Small and X-Large not FDA-reviewed

The SNOO was originally authorized through De Novo classification (DEN210039) with a specific indication: facilitating a supine sleep position in infants from birth to 6 months of age who cannot yet roll over, for home use.¹ That authorization covered three sleep sack sizes — Small (5–12 lbs), Medium (12–18 lbs), and Large (18–25 lbs).

Happiest Baby subsequently introduced two additional sizes without first obtaining FDA clearance. The X-Small Sleep Sack, designed for infants 4–8 lbs, is 44 cm long and 21 cm wide at the chest, 5 cm shorter and 2 cm narrower than the Small sack the FDA reviewed.¹ The FDA concluded that these dimensional reductions meaningfully increase risk: the X-Small sack may be too constrictive for a 5–8 lb infant who would otherwise wear the Small size, potentially compressing vital organs, limiting diaphragmatic movement, and causing respiratory compromise.¹ The agency also noted that the X-Small sack extends the device's intended population to include infants as light as 4 lbs, a birthweight range that encompasses a higher proportion of preterm infants, who already carry elevated SIDS/SUID risk.¹

The X-Large Sleep Sack, marketed for infants 23–25 lbs, presents an inverse set of risks.¹ At 68 cm long and 29 cm wide at the chest, 7 cm longer and 1 cm wider than the Large sack, the X-Large introduces excess fabric that may ride up and cover an infant's mouth or neck, raising the risk of respiratory compromise, suffocation, or death.¹ The larger dimensions may also make it easier for an infant to break free from the sack and assume an unsafe position within the bassinet.

The FDA noted in the Warning Letter that Happiest Baby launched the X-Small as a beta program specifically in response to customer complaints that the Small sack was too large on their infants — evidence, the agency wrote, that the company introduced the change with the intent to affect safety or effectiveness, a threshold that triggers the premarket submission requirement.¹

SNOO Hospital Bundle: change in intended use without premarket review

The original De Novo authorization for the SNOO explicitly limited use to home settings. Despite this, the FDA found that Happiest Baby has been actively marketing a SNOO Hospital Bundle, which includes the bassinet, a wheeled mobility cart, a reusable sealed mattress, bassinet mesh covers, and multiple sleep sacks, to clinical facilities including NICUs.¹

Marketing materials reviewed by FDA investigators stated that the device keeps infants safely on their backs, models American Academy of Pediatrics safe sleep guidelines, and was positioned in company documents as superior to standard hospital bassinets.¹ The FDA determined that marketing a home-cleared device into hospital environments, with their distinct infection control protocols, industrial cleaning agents, and patient populations that include medically complex neonates, constitutes a major change in intended use requiring premarket review.¹

The wheeled mobility cart also introduced new risks not evaluated in the original authorization.¹ Unlike the fixed-base home bassinet, a cart-mounted device creates potential for tipping, rolling, or instability during transport, with wheel-lock failure posing a risk of uncontrolled movement while an infant is present.

Quality system failures: mold, unsanitary refurbished units, and inadequate complaint handling

Beyond the unauthorized device modifications, the FDA documented 6 categories of Quality System Regulation violations. Of particular clinical relevance: the agency found that Happiest Baby had received multiple complaints of stains, soiling from bodily fluids, and unsanitary conditions on refurbished SNOO units sent to customers.¹ An internal inspection of the refurbisher's output found that 100% of units sampled failed to meet the company's own quality standards. The FDA noted that improperly cleaned bassinets used with infants, who have immature immune systems, may serve as a reservoir for pathogens that can cause local or systemic infection.¹

The agency also found that the company had grouped numerous individual complaints into single Product Experience Reports, limiting the scope of investigation for each case.¹ One grouped report, PER-000060, combined multiple complaints about sleep sacks being too large for infants, including at least one report that a sack was "riding up and seem[s] like it is choking baby." The company attributed all complaints to user error and, notably, developed the X-Small Sleep Sack as an internal fix rather than conducting a formal corrective investigation or filing a mandatory Medical Device Report.¹

The FDA also identified failures in design validation: safety testing was conducted using only average-sized infant models, with no testing at the lower or upper bounds of the authorized 5–25 lb weight range.¹ Design validation for the SNOO Leg Lifters, an accessory that inclines the bassinet, was performed using an outdated sleep sack design that predated the De Novo authorization.¹ Neither the X-Small nor X-Large sleep sacks underwent design validation before distribution.

What clinicians and caregivers should do now

The FDA is urging clinicians, caregivers, and health care providers to avoid using the X-Small and X-Large sleep sacks and the SNOO Hospital Bundle until they have completed FDA review.¹ Reports of injuries, malfunctions, mold, or unsanitary conditions related to any SNOO product should be submitted through the FDA MedWatch Voluntary Reporting Form. The agency has given Happiest Baby 15 business days to respond with a corrective action plan and has indicated that failure to adequately address the violations could result in seizure, injunction, or civil monetary penalties.¹

Reference

1. US Food and Drug Administration. Warning Letter: Happiest Baby, Inc. MARCS-CMS 718306. Issued June 15, 2026. Accessed June 15, 2026. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/happiest-baby-inc-718306-06152026