Mont. Code Ann. § 46-19-203

If there is good reason to suppose that a woman against whom a judgment of death is rendered is pregnant, the sheriff of the county, with the concurrence of the judge of the court by which the judgment was rendered, shall summon a jury of three physicians to inquire into the supposed pregnancy. Immediate notice of this inquiry must be given to the county attorney of the county who must attend the inquiry and may produce witnesses.