> My conclusion in cross-referencing [1] is that your "embryo proper" is around stage 4-5 and would have been implanted? No, I believe what happened is that th

> My conclusion in cross-referencing [1] is that your "embryo proper" is around stage 4-5 and would have been implanted? No, I believe what happened is that they made their mitochondrial changes before the pronuclei fusion, and inserted this modified egg into the womb. There it the continued on with the fertilization process, finishing up, creating the zygote, etc. The embryo-proper bit was only relevant to the "from what point is it a human life" part of this, it is not relevant to the procedure specifically. That comes a whole week after fertilization I believe.