If you are considering abortion, it is better to plan for adoption than abortion, unless the baby may be deformed or have terrible suffering. Even so, there is no comparison between that suffering and the suffering of a hell realm. It is better to be born in the human realm, even for one day.
Having an abortion could shorten both your lives, as one of the results of killing. The negative karmic effects of killing also include many diseases—even food could cause you disease.
It is also an unpleasant thing for the child. If the child were to go to a better rebirth or to a pure land, there would be something better than this life for the child. But we can’t tell. So it is better off here in the human realm than in a worse realm.