In an extended parable, God remarks on the heartlessness of people who fail to give newborn children the proper compassionate care that they should receive:
Eze 16:4 And as for thy nativity, in the day thou wast born thy navel was not cut, neither wast thou washed in water to supple thee; thou wast not salted at all, nor swaddled at all.
5 None eye pitied thee, to do any of these unto thee, to have compassion upon thee; but thou wast cast out in the open field, to the lothing of thy person, in the day that thou wast born.
6 And when I passed by thee, and saw thee polluted in thine own blood, I said unto thee when thou wast in thy blood, Live; yea, I said unto thee when thou wast in thy blood, Live.
This passage makes clear that God wants compassionate care given to newborn babies so that they would live. When such care is not given to them, it reveals the heartlessness of those who refuse to pity them and have compassion on them.
Arguing from the lesser to the greater, how much more heartless is it not just to fail to give compassionate care to newborns but also to take steps to kill them. In the same way, aborting an unborn baby displays the heartlessness of those who put to death a human being who is helpless, innocent, and undeserving of such inhuman treatment.
O God, please bring to an end the heartlessness of abortion and infanticide. Have mercy on these helpless babies. Work in the hearts of those who are doing these heartless things so that they will repent and believe in your Son.
Come quickly, O Christ, for the sake of these who are being mercilessly slaughtered. Hear their cries, O Father.