Generally, they cannot regain parental rights. (Think of what this process would do to the child or children.) Except, possibly, by using one of the recognised bases for seeking a post-judgment remedy, such as error in calculation, fraud on the court, a new appellate opinion renders the judgment in your case no longer good law, and a few others. There are time restrictions on bringing such a motion, and courts do not like them.
Answered on Jun 16th, 2015 at 4:53 PM