These are a soft jersey knit, with fully finished edges and sturdy snaps.  The measurement from the neck to the crotch (taken from the back) is 7 inches after washing.  From working with preemies as an RN (many years ago, and as a float nurse from pediatrics), I'd guess that these would fit a preemie up to 2.5 pounds (allowing room for diapers).  I collect realistic baby dolls, so my 'babies' don't grow- but if you have the time to get these, they are very cute, and only took about a week to get here from the UK.