Is the Advance Directive honored by my attending physician if I am pregnant?

Oklahoma law provides that a person who has been diagnosed as pregnant and whose attending physician is aware of the diagnosis will be provided with life-sustaining treatment and artificially administered hydration and nutrition unless the person has, in her own words, specifically authorized that during a course of pregnancy, life-sustaining treatment and/or artificially administered hydration and/or nutrition shall be with­held or withdrawn.