 Relying on examinations of miscarried fetuses, Aristotle believed that male fetuses acquire their basic form at around day 40, and female ones at day 90.For Pythagoreans, however, fetal life was co-equal in moral worth with adult human life from the moment of conception; similar views were held by Stoics.Ancient Athenian law did not recognise fetal right to life before the ritual acknowledgement of the child.