Newborn blankets regardless of how they are made should be no bigger than a 3 foot BY 4.5 foot rectngle, and no smaller than a 2 foot square.
Children's Chemotherapy caps can be sewn, knit or crocheted, and must measure between 12-18 in height. They can include a brim just like the one in the picture, and to be consider acceptable must measure a circumfernce of 22-27 inches.
Preemie Hats can be knit or crocheted, and should be 8-11 inches in circumference, and measure 5-7 inches in height.
Newborn hats should be a little bigger; measuring around 13-16 inches in circumference, and 7.5-11 inches in height.