Guardianship in case of divorce or judicial separation

In any case where a decree for judicial separation, or a decree nisi or absolute for divorce, is pronounced, the court pronouncing the decree may, in exceptional circumstances, and if it is in the best interests of the child, thereby declare the parent by reason of whose misconduct the decree is made to be a person unfit to have the custody of the child, if 22 any, of the marriage and, in such case, the parent so declared to be unfit shall not, upon the death of the other parent, be automatically entitled as of right to the custody or guardianship of such child; provided that the court may, if satisfied, determine whether there has been a change of circumstances necessitating the grant of custody or guardianship to such