Hullin 69: The Fetus and Its Complications for Slaughtering, Exchange, and the Sanctity of the First-Born

More on a fetus that extends a limb from its mother's womb and brings it back inside. What if that takes place in between the severing of the first "siman" and the second "siman" in slaughtering the mother. Will the progeny of that fetus (after it grows up) need slaughtering, though that animal itself does not require slaughtering? Also, complications of this kind of animal when it comes to exchange (temurah) for another animal that was not born with the same unusual status. Plus, the first-born (bekhor) - when it's the fetus in these kinds of cases, where it might even be dismembered to help it out of the womb (and then it isn't a bekhor after all, unless the majority of it came out whole).