In a healthy pregnancy your HCG levels should double every 48 hours. But when the pregnancy is not progressing the way it should as in the case of chromosomal abnormality your HCG may rise at slower rates or rise at first and then start to decline.
Definition of moot. 1 : a deliberative assembly primarily for the administration of justice; especially : one held by the freemen of an Anglo-Saxon community.
mootness doctrine n. : a doctrine in judicial procedure: a court will not hear or decide a moot case unless it includes an issue that is not considered moot because it involves the public interest or constitutional questions and is likely to be repeated and otherwise evade review or resolution.