The distinction between decriminalizing and liberalizing abortion is very precarious.
To decriminalize means that abortion escapes penal sanction, which does not mean inevitably that it is permitted. Some analogous cases, of a lesser order it is true, are known: one does not punish the theft of bread committed by a starving poor person; one does not thereby declare that it is permitted. But in a democratic society in which, so to speak, whatever is not forbidden is permitted, to decriminalize abortion means to declare it unpunishable, which is the practical equivalent of authorizing it.
Liberalizing abortion, is to connect it to individual liberties or rights.
To decriminalize abortion means to accept it, and acknowledge it an established right: It is to legalize it, covering it with the authority of law. Hence, it means to deprive the unborn infant of all legal protection concerning his very existence. Criminalizing abortion is but the logical consequence which such protection ought to offer the unborn infant.