I would hazard to guess that the reason that the clinic workers refused to call is that this type of thing is "business as usual." A mother would have to be awfully cold to look at a newborn like this and be able to justify it being just "a lump of tissue."
The workers ignored her cries because they would instantly become liabel due to the 'born alive infants protection act' ... they ignored the woman because they are in the business of serial killing and haven't a clue how to save a premature baby nor do they have ANY desire to save a child.