Why is the Catholic Church against abortion?

The Catholic Church teaches that abortion is the killing of another human person. This is the primary reason why the Church is against it.

The Catholic Church remains one of the few voices left that oppose abortion in the world, and is often questioned about it.

Why is the Catholic Church against abortion?

The Catechism of the Catholic Church gives a detailed reason why the Church opposes abortion.

Human life must be respected and protected absolutely from the moment of conception. From the first moment of his existence, a human being must be recognized as having the rights of a person — among which is the inviolable right of every innocent being to life.
Since the first century the Church has affirmed the moral evil of every procured abortion. This teaching has not changed and remains unchangeable. Direct abortion, that is to say, abortion willed either as an end or a means, is gravely contrary to the moral law
CCC 2270-2271

St. John Paul II wrote in Evangelium Vitae about how abortion is often called different names by society to make it appear that it is not the killing of another person.

Especially in the case of abortion there is a widespread use of ambiguous terminology, such as “interruption of pregnancy,” which tends to hide abortion’s true nature and to attenuate its seriousness in public opinion. Perhaps this linguistic phenomenon is itself a symptom of an uneasiness of conscience. But no word has the power to change the reality of things: procured abortion is the deliberate and direct killing, by whatever means it is carried out, of a human being in the initial phase of his or her existence, extending from conception to birth.

Abortion is a direct violation of the commandment of God, “Thou shalt not kill.”

At the same time, while the Church is against abortion, the Church tries to do everything in her power to protect women and support them. The Church does not think women should be abandoned or discarded, but that the human family needs to embrace all women and care for them when they are in crisis.

The Church is against abortion not because she hates women, but because she believes every human life should be protected and that killing another human person is wrong.