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As it turns out, at the latest possible moment for an RU 486 abortion, nine weeks into a pregnancy — say, eight weeks fetal age, allowing generously for unusual variation in fertilization dates — there is no brain function whatsoever. Even the most rudimentary electrical activity in the brain, the kind that your average frog possesses, will not even become remotely possible until ten weeks, and it has never been actually detected before twelve weeks.
So, assuming both extremely precocious embryonic development and early fertilization, the embryo is still a full two weeks away from brain life. Under a more realistic scenario, the safety margin is five weeks, and if the French standards of distribution were adopted, that figure would be pushed to seven weeks.
And recognizably human brain activity absolutely cannot, under even the most fantastic circumstances, occur less than twelve weeks after RU-486 ceases to be effective. Most probably, it will be at least six months after, or even later.