"The Bible does not even discuss the abomination of intentionally causing an abortion on purpose."
Oh sure it does, there are several references to the sacrifice of children on the altar of Moloch, which is what the pagans in the region (and the pagans of this region, too) were/are doing.
Those sacrifices were of children who had already been born - but your fundamental point is valid. It's a question of timing: there is no moral difference.