A monstrous birth, variously defined in history, is a birth in which a defect renders the animal or human child malformed to such a degree as to be considered "monstrous". Such births were often taken as omens, signs of God, or moral warnings to be wielded by society at large as a tool for manipulation in various ways. The development of the field of obstetrics helped do away with spurious associations with evil but the historical significance of these fetuses remains noteworthy. In early and medieval Christianity, monstrous births were presented as and used to pose difficult theological problems about humanity and salvation.