So much crazy sh*t happens in the womb that "pro-life" states are going to have to come up with nuanced rules about, once the training wheels of Roe v. Wade fall away, and I have no confidence they are ready for it.
The most sensible way to treat the "death" of one of multiple siblings in the womb is to simply classify it as a kind of miscarriage. No one ought to be legally responsible, since it's "just mother nature at work." It won't do to blame the mother, since she had no intention to lose a twin. It also won't do to blame the surviving twin, since an early fetus in the womb is incapable of having any thoughts at all (no brainwave activity can be detected until the 3rd trimester), let alone any thoughts of murder.
But in practice, any state that chooses to prosecute women for having abortions will certainly end up falsely prosecuting natural miscarriages, since our justice system has never produced outcomes perfectly aligned with innocence and guilt.
Some overzealous prosecutors looking to make a name and a political career will compete with each other to see who can be the "toughest" on abortion. They'll argue that there's no real way to tell between a natural miscarriage and a voluntary miscarriage (i.e. an abortion), and so every women to whom this happens ought to be hauled into court and made to testify about the most intimate happenings of her body in front of a jury of her peers.
This is what pro-choice people mean when they say states that ban abortion from the moment of conception will turn "every womb into a potential crime scene." It's not an idle phrase.
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