The agency cited the manufacturer for distributing new sleep sack sizes and a clinical bassinet bundle without required clearance, alongside quality system and reporting violations.

Key takeaways:

• The FDA issued a warning letter to Happiest Baby, Inc for marketing X-Small and X-Large SNOO sleep sacks and a SNOO Hospital Bundle without proper agency authorization.
• The unauthorized sleep sack sizes pose increased risks to infants, including potential respiratory compromise and suffocation, due to dimensional changes not evaluated in the device’s original clearance, according to the FDA.
• Marketing the SNOO for hospital use fundamentally alters its intended environment, introducing new risks related to infection control protocols and mobility cart stability.
• The manufacturer was also cited for quality system violations, including inadequate complaint handling regarding reports of mold and soiling on refurbished devices.

The US Food and Drug Administration (FDA) issued a warning letter on June 15, 2026, to Happiest Baby, Inc, the manufacturer of the SNOO Smart Sleeper, citing multiple violations that include the distribution of unapproved sleep sack sizes and a hospital bassinet bundle.

The SNOO Smart Sleeper was originally authorized for home use to facilitate a supine sleep position for infants up to 6 months old, utilizing three specific sleep sack sizes (small, medium, and large). However, an FDA inspection revealed the company introduced X-Small (4-8 lbs) and X-Large (23-25 lbs) sleep sacks without submitting the required premarket notification (510(k)).

According to the FDA, the dimensional changes in the unapproved sleep sacks significantly alter the device’s risk profile. The X-Small sleep sack poses a risk of compressing vital organs and limiting diaphragmatic movement, while the X-Large size increases the risk of the fabric riding up and covering an infant’s mouth or neck, potentially leading to respiratory compromise or suffocation.

The warning letter also addressed the SNOO Hospital Bundle, which is marketed for clinical settings. The FDA stated that transitioning the device from home use to hospital use, including in neonatal intensive care units, constitutes a major change in intended use. The hospital environment introduces unique challenges, such as the need for hospital-grade cleaners that could degrade device components, and the inclusion of a wheeled mobility cart that presents new risks of tipping or rolling during transport.

Additionally, the FDA cited Happiest Baby for quality system regulation violations. Investigators found the company inadequately handled customer complaints by grouping multiple reports—such as instances of mold on mattresses or sleep sacks being too large—without evaluating each case individually.

The firm also failed to submit required reports to the FDA within 10 working days after initiating a correction to replace stained and soiled refurbished SNOO devices. The agency noted that improperly cleaned SNOO devices can pose health risks for the vulnerable infant population, as exposure to contaminated surfaces and bodily fluid stains may cause local and systemic infections.

The FDA has requested a written response from Happiest Baby outlining the specific steps the firm has taken to address the noted violations and prevent their recurrence.

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