open system theory applied to evolution., page-17

For Mary’s child to be a true descendant of her ancestors Abraham, Judah, and David, as God had promised, her ovum had to contribute toward her pregnancy. (Gen. 22:15, 18; 49:10; 2 Sam. 7:8, 16) However, Jehovah’s holy spirit was used in transferring the perfect life of God’s Son and causing the conception. (Matt. 1:18) It would appear that this canceled out any imperfection existing in Mary’s ovum and from the very start protected the developing embryo from anything hurtful.