Additional Gauge Information:

fingering weight (small preemie):
US C/D crochet hook
yarn:
white - 1 ounce
yellow - a few yards
blue - a few yards
gauge: 11 dc = 5 cm (2”)

DK weight (medium/large preemie):
US E/F crochet hook
yarn:
white - 1 ounce
yellow - a few yards
blue - a few yards
gauge: 9 dc = 5 cm (2”)
worsted weight (newborn):

US F/G crochet hook
yarn:
white - 1 ounce
yellow - a few yards
blue - a few yards
gauge: 6.5 dc = 5 cm (2”)
all yarn requirements are approximate

There is also a pattern for a matching sweater, and a pattern for a matching set of slippers that can be found here.

Direct pdf link: http://www.p2designs.com/pdfs/ForgetHat.pdf