If the father or mother abuses or willfully abandons the child, or if significant difficulty or impropriety in the father's or mother's exercise of parental authority otherwise greatly harms the interests of the child, the family court may issue a ruling affirming the father's or mother's loss of parental authority, at the request of the child, a relative thereof, the guardian, the guardian supervisor, or the public prosecutor; provided, however, that this does not apply if cause for such a ruling is expected to cease to exist within two years.