As no right can have meaning without the ability to exercise it, life is by rational necessity preeminent among them. In recognition of that, the willful abrogation of it carries the most severe penalty a social compact can impose. And even then many argue against it. Abortion doesn't approach the litmus in nearly any case and by no means as the rule.
What of a litmus test for the assignation of this right for the unborn? Your applied instinct, under begrudged circumstance, seem to indicate a failure for such.
Is your presumption, against such, not an out-of-hand arbitrary abstention of the very standard you otherwise regard?