Didache (1st Century) 2:2:
do not murder a child by abortion or kill a new-born infant.
Epistle of Barnabas (1st Century) Chapter 19:
Thou shalt not slay the child by procuring abortion; nor, again, shalt thou destroy it after it is born.
Athenagoras’ Plea for the Christians (Late 2nd Century) Chapter 35:
we say that those women who use drugs to bring on abortion commit murder, and will have to give an account to God for the abortion
Find more of what the early Christians thought on my Christian History page!