Zach, being a preemie, had teeny tiny feet and ankles.  He was actually a kinda big preemie, weighing in at 5 lbs. 11 oz., but still there were no socks to fit him.  He had a yellow pair that the hospital gave him but needed more.  I tried soooooooo many patterns and nothing fit him so I did what I should have done first – I measured him and made socks custom to his foot.