Why is macduff able to kill macbeth

In the story "Macbeth" the 3 witches told the prophecy that Macbeth would not be able to be killed by any man born from his mother's womb. Macbeth takes this as a sign that he can not be killed by anyone but we find out that Macduff was technically born by a C-section meaning that although he was born from his mother, he was not born traditionally and was considered to not be born by the womb. I hope this helped!