Lately, I happened to be reading a bit on the conjoined twin case of Jodie and Mary when I began to consider the situation of fetus in fetu, one theory for which is that it is the result of a twin being basically absorbed into another twin in the uterus. It remains “alive” in some sense, if it has blood flowing to it, but in all cases the fetus is undeveloped, though it may even have a partial brain and many other parts.
Now, in all cases, I’ve searched through bioethics sites and forums, and though it may just be because of how rare it is (less that 90 cases are known), I’ve never seen anyone sayings something like, the fetus in fetu has a right to life and shouldn’t be removed from the twin they are parasitizing even if the fetus doesn’t have a brain…well, except on this forum (of course). This post seems to express some concern that cutting the umbilical cord of a fetus in fetu may have been immoral, and this one seems to say outright that the fetus in fetu should not be removed unless it is a danger to the person (though whether this person means lowering their quality of life or actually endangering their live, I don’t know).
No one else has apparently ever even entertained the idea that a fetus in fetu should not be removed, and personally I think it is insane that anyone would, but I can understand why Catholics would be the only ones who would do so, because the Church demands an absolute understanding of life beginning at conception (something Aquinas, for example, didn’t believe).
Still, since I haven’t seen any actual bioethecists at all, let alone Catholic ones, try to say that a fetus in fetu should not be removed, I’m assuming that even the Church would not object to it were such situation to occur in their hospitals. I suppose if pressed, some theologian might bring in the double effect, saying that even if the fetus in fetu is a life, by cutting it out, we don’t intend its death, its death is just a foreseen but not not intended consequence of removing it from the host twin.
But this leads me to wonder, how is separating the fetus in fetu from the host different from a direct abortion when the mother’s life is endangered? Is it because the situation is unnatural? Is it because the fetus in fetu can never be “delivered” from the host body by any other means? Is it because the fetus ceased growing (though in some cases they do grow)? And, even though I doubt this is even possible, if such a fetus was simply causing health problems but not directly endangering the life of the person, would the double effect not apply, making it immoral to cut it out?
Note that I’m not talking about cases where the fetus was removed without the doctors knowing what it was before they removed it, I’m talking about a case where they were aware like this one.