Catechism of the Catholic Church
2270 - 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.72
Before I formed you in the womb I knew you, and before you were born I consecrated you.73
My frame was not hidden from you, when I was being made in secret, intricately wrought in the depths of the earth.74
2271 - 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:
You shall not kill the embryo by abortion and shall not cause the newborn to perish.75
God, the Lord of life, has entrusted to men the noble mission of safeguarding life, and men must carry it out in a manner worthy of themselves. Life must be protected with the utmost care from the moment of conception: abortion and infanticide are abominable crimes.76
72 - Cf. CDF, Donum vitae I,1.
73 - Jer 1:5; cf. Job 10:8-12; Ps 22:10-11.
74 - Ps 139:15.
75 - Didache 2,2:SCh 248,148; cf. Ep. Barnabae 19,5:PG 2 777; Ad Diognetum 5,6:PG 2,1173; Tertullian, Apol. 9:PL 1,319-320.
76 - GS 51 § 3.