I made this 3 years ago for Embryology class, and I was inspired by the Knitted Digestive System to post it here. The concept is ripped off of Popples, those vaguely mammalian stuffed toys that 20-somethings might remember; they could turn inside-out with a little pouch-thing on their back, so that all you could see is their tail sticking out of a little ball. I thought the gimmic would be a useful way of illustrating the various pouch-within-a-pouch structure of fetal membranes.
So, here he is in action...
Here's the concept of how the fetus would look in situ. Imagine one end of the chorion and amnion have been sliced off, along with the chorion's connection to the uterus around the borders of the placenta.
And finally, some pictures with the bits labelled.
Caveat: I think I could have done a better job with the face; the fetal face is a mess of lumps and weird bulges at this point, and if I were to make it again, I'd probably make a Sculpy head and sew it onto a stuffed body (like an embryonic version of a real doll...). I apologize for any anatomical errors I may have committed; there's no excuse for that, I just suck.