SwaddleDesigns Transitional Swaddle Sack — Arms Up Sleeves, 0-3 Months, Blue Tiny Triangles

Soft, wearable transition for your newborn

The Transitional Swaddle Sack from SwaddleDesigns makes the move from a traditional swaddle to a wearable blanket gentle and practical for both baby and caregiver. The arms-up design invites familiar self-soothing motions while the half-length sleeves with fold-over mitten cuffs offer adjustable coverage. Because the baby can still move their arms if they roll, the sack is designed with growth in mind, helping transitions feel natural rather than abrupt. The breathable 100% cotton fabric and a lightweight TOG 0.5 create a comfortable climate for daytime naps and night-time rests alike, while the two-way zipper system provides quiet, efficient diaper changes from top or bottom. The patent-backed construction reflects a nurse-designed approach focused on ease, safety, and daily usability.

What makes this transitional swaddle different

• The arms-up sleeve design gives babies room to self-soothe while keeping arms close for a secure feel.
• Half-length sleeves with foldover mitten cuffs can be worn open or closed to tailor coverage.
• The cuffs provide partial suppression of the startle reflex to help settle baby more quickly.
• Hip-healthy, snug fit supports natural leg posture while still being easy to move in.
• The 2-way zipper opens at the top for easy entry and at the bottom for quick diaper changes.
• A true wearable blanket, not a tight wrap, with a design suited for rolling babies.

Real-world use and daily life

Ideal for babies who sleep best with arms up, those starting to roll, or infants who break out of a traditional swaddle. The design accommodates transitions after feedings, simplifies travel with a compact, secure layer, and supports both daytime naps and overnight rest. The mittens can stay closed to protect delicate facial skin or be opened for hand-to-mouth self-soothing as desired. With weight-based sizing, caregivers can pick the right fit as baby grows, keeping a snug yet comfortable feel without restricting movement.

Care, sizing, and safety notes

• Sizes are weight-based: S 6–14 lb (0–3 months), M 14–21 lb (3–6 months), L 21–24 lb (6–9 months).
• Made of 100% cotton with TOG 0.5 for breathable comfort; machine washable and easy to care for.
• US Patent 11,812,795 with international patents backs the thoughtful, nurse-designed design.

Use this transitional step between traditional swaddling and a wearable blanket to support a calm, comfortable sleep routine while offering flexible coverage as baby grows.