Sounds like it's pretty much the whole length of the cord. I'd mention it to my OB (as well as anybody else in the practice who is likely to be covering for him/her when the time comes) in advance so as to forestall the placenta's being pitched in the trash before the cord's been removed. They're pretty slimy, so a ziploc bag will come in handy for getting it home, and I'd keep it refrigerated if it's going to more than a couple of hours until you can get somewhere to lay it out to dry. No idea whatsoever as the final shape, but clearly the dimensions need to fit in the container supplied.