I bought these as long underwear for my 8 month old (large) grandchild.  The message now is clear:  no blankets for infants.  So I made a flannel lined fleece bunting for her to sleep in.  Because she lives in Upstate New York where it gets cold, I wanted her to have an additional cotton layer for extra warmth.  These long johns fit the bill.  They are well made, soft and cozy.  If I had to say anything about size, I'd say these run a little bigger than most 18 month clothes but that's fine with me.