According to reports on SIDS, a Cocoon or Sleep Sack is a safer alternative to a blanket and they are just as easy to make.

Cocoon ©Linda Butler 2012

Sizes: Preemie or Small 0-3mths (Full Term).
Finished Measurements: 18″x21″, (20″x23″) approx . (folding the top down for a better fit is not recommended).

Materials: Category 4 Worsted Weight yarn (shown in Caron One Pound Yarn), Size US9/UK5/5.5mm) needles.

Gauge: 4sts/5rows to 1″ in Stockinette Stitch.

Pattern Stitch: Keep the first and last stitches as edge stitches (I like to slip the first st of every row and knit the last st.).
Row 1: S1, *K1, P1 Repeat from * to end.
Row 2: S1, Knit to end.

Instructions: Cast on 73sts (81sts) and work 4 rows back and forth/flat in Garter Stitch (knit every row).
Rows 5-9: Start working pattern stitch rows.
Row 10:  Maintain pattern and increase 1 stitch at each end. 75sts (83sts).
At this point you can continue on two needles and seam the center front or you can work in the round.
To work in the round join by slipping the last stitch over the first stitch decreasing 1 stitch (74, 82sts).
Continue in pattern until work measures 17″ (19″) from beginning [length can be adjusted here].
Decrease Row 1: K2tog to end, (37, 41sts ).
Work 1 row after each decrease row.
Decrease Row 2: K2tog to last st K1, (19, 21sts ).
Decrease Row 3: K2tog to last st K1 , ( 10, 11sts ).
Cut yarn long enough to thread through remaining stitches on needle and weave in ends.

Optional: Add a Matching Hat