Sanhedrin 91b:
Antoninus asked Rabbi, "At what time does the impulse to evil gain mastery over
man: at the time of his conception or at the time he is born?"
Rabbi: "At the time of his conception."
Antoninus: "If so, he would have kicked his way out of his mother's womb.
Accordingly, the impulse to evil must gain mastery at the time of birth."
Subsequently, Rabbi used to say: This is one thing that Antoninus taught me, and
Scripture supports him, for it is said, "At the
door [through which the newborn child issues], sin crouches" (Bereishit
4:7).