Early Church on Abortion

 “the law orders all the offspring to be brought up, and forbids women either to cause abortion or to make away with the fetus”
Jewish historian, Josephus  (Against Apion 2.202).

"Thou shalt not kill. Thou shalt not commit adultery; thou shalt not corrupt
boys; thou shalt not commit fornication. Thou shalt not steal. Thou shalt not
use witchcraft; thou shalt not practice sorcery. Thou shalt not procure
abortion, nor shalt thou kill the new-born child. Thou shalt not covet thy
neighbor's goods."
Didache 2:2, 1st century

"Thou shalt not murder a child by abortion, nor again shalt thou kill it when it is born. 
Epistle of Barnabas 19:5, early 2nd century

"those who use abortifacient medicines to hide their fornication cause not only the outright murder of the fetus, but of the whole human race as well"  St. Clement of Alexandria Paedogus 2:10.96.1, 2nd century

"And when 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, on what principle should we commit murder? For it does not belong to the same person to regard the very fetus in the womb as a created being, and therefore an object of God's  care, and when it has passed into life, to kill it; and not to expose an infant, because those who expose them are chargeable with child murder, and on the other hand, when it has been reared to destroy it." 
Athenagoras the Athenian, A Plea for the Christians, 177 A.D.

"In our case, murder being once for all forbidden, we may not destroy even the fetus in the womb, while as yet the human being derives blood from other parts of the body for its sustenance. To hinder a birth is merely a speedier man-killing; nor does it matter whether you take away a life that is born, or destroy one that is coming to the birth. That is a man which is going to be one; you have the fruit already in its seed." 
Tertullian, Apology, 21 c. 200 A.D.

Chapter 25. Tertullian Refutes, Physiologically, the Notion that the Soul is Introduced After Birth (includes descriptions of abortion procedures in that time)
"http://www.newadvent.org/fathers/0310.htm"

"And the hearers of Callistus being delighted with his tenets, continue with him, thus mocking both themselves as well as many others, and crowds of these dupes stream together into his school. Wherefore also his pupils are multiplied, and they plume themselves upon the crowds (attending the school) for the sake of pleasures which Christ did not permit. But in contempt of Him, they place restraint on the commission of no sin, alleging that they pardon those who acquiesce (in Callistus' opinions). For even also he permitted females, if they were unwedded,  and burned with passion at an age at all events unbecoming, or if they were not disposed to overturn their own dignity through a legal marriage, that they might have whomsoever they would choose as a bedfellow, whether a slave or free, and that a woman, though not legally married, might consider such a companion as a husband. Whence women, reputed believers, began to resort to drugs  for producing sterility, and to gird themselves round, so to expel what was being conceived on account of their not wishing to have a child either by a slave or by any paltry fellow, for the sake of their family and excessive wealth.  Behold, into how great impiety that lawless one has proceeded, by inculcating adultery and murder at the same time! And withal, after such audacious acts, they, lost to all shame, attempt to call themselves a Catholic Church!"
St. Hippolytus, Refutation of All Heresies, 7, c. 200 A.D.

"You may see many women widows before wedded, who try to conceal their miserable fall by a lying garb. Unless they are betrayed by swelling wombs or by the crying of their infants, they walk abroad with tripping feet and heads in the air. Some go so far as to take potions, that they may insure barrenness, and thus murder human beings almost before their conception. Some, when they find themselves with child through their sin, use drugs to procure abortion, and when (as often happens) they die with their offspring, they enter the lower world laden with the guilt not only of adultery against Christ but also of suicide and child murder." 
St. Jerome, Letter 22 To Eustochium, 13, 384 A.D.

CHAPTER XXIII. The Reality of the Resurrection
84. Now, with respect to the resurrection of the body—and by this I do not   mean the cases of resuscitation after which people died again, but a       resurrection to eternal life after the fashion of Christ's own body—I have not found a way to discuss it briefly and still give satisfactory answers to all the  questions usually raised about it. Yet no Christian should have the slightest  doubt as to the fact that the bodies of all men, whether already or yet to be born, whether dead or still to die, will be resurrected.
 
85. Once this fact is established, then, first of all, comes the question about abortive fetuses, which are indeed "born" in the mother's womb, but are never so that they could be "reborn." For, if we say that there is a       resurrection for them, then we can agree that at least as much is true of fetuses that are fully formed. But, with regard to undeveloped fetuses, who would not more readily think that they perish, like seeds that did not       germinate?  But who, then, would dare to deny—though he would not dare to affirm it either—that in the resurrection day what is lacking in the forms of things will be filled out? Thus, the perfection which time would have accomplished will not  be lacking, any more than the blemishes wrought by time will still be present.  Nature, then, will be cheated of nothing apt and fitting which time's passage would have brought, nor will anything remain disfigured by anything adverse and contrary which time has wrought. But what is not yet a whole will become whole, just as what has been disfigured will be restored to its full figure.

86. On this score, a corollary question may be most carefully discussed by the most learned men, and still I do not know that any man can answer it, namely: When does a human being begin to live in the womb? Is there some form of       hidden life, not yet apparent in the motions of a living thing? To deny, for example, that those fetuses ever lived at all which are cut away limb by limb and cast out of the wombs of pregnant women, lest the mothers die also if the       fetuses were left there dead, would seem much too rash. But, in any case, once a man begins to live, it is thereafter possible for him to die. And, once dead, wheresoever death overtook him, I cannot find the basis on which he would not  have a share in the resurrection of the dead. 
St. Augustine, Enchiridion,23,84-86

Sources: Roots of the Faith,  Mike Aquilina

"http://ldysinger.stjohnsem.edu/@books/Jones_soul/05_med_penal.htm"

"http://www.christiananswers.net/q-eden/edn-abortioninthebible.html"