Hi, I am making preemie blankets...my sister is a NICU nurse. The ones I'm making are 18x24 finished. She is a transport nurse and they don't need all the extra fabric to deal with. Being rectangle fits their little bodies better.
She also told me not to use "blue" because it distorts the baby's coloring. She showed me some prints at Hancocks that would work well. Mostly neutral background with spaced tiny designs. Also she recommended the cuddly cotton flannel because it helped keep the heat in their little bodies..I also agree with the no batting. They wrapped the babies in the cocoon style.