Whenever possible a child should not be denied the right to both a mother and father and the State should not implement policies, for the sake of modernity, which create artificial constructs where a child will be fatherless or motherless.
There are plenty of circumstances where the State intervenes through law to deny the right of a child and it's Father for example. The law is currently all on the Mother's side.
A child should not be denied the right to both it's parents whether that be a mother and father, two mothers or two fathers.