(a) An appeal from any final order or decree rendered under this subchapter may be taken in the manner and time provided for appeal from a judgment in a civil action.
(b) Subject to the disposition of an appeal, upon the expiration of one (1) year after an adoption decree is issued, the decree cannot be questioned by any person including the petitioner, in any manner upon any ground, including fraud, misrepresentation, failure to give any required notice, or lack of jurisdiction of the parties or of the subject matter unless, in the case of the adoption of a minor, the petitioner has not taken custody of the minor or, in the case of the adoption of an adult, the adult had no knowledge of the decree within the one-year period.