If children cannot move on to their permanent families then they are not freeing up foster care placements for other vulnerable children who are entering the care system.
Os na all plant symud ymlaen i'w teuluoedd parhaol, yna nid ydynt yn rhyddhau'r lleoliadau gofal maeth i blant eraill agored i niwed sy'n ymuno â'r system ofal.