Hippocrates, the “father of medicine,” lived 460-377 B.C. He crafted the Hippocratic Oath that has been required of medical students around the world as a condition of graduation.
The Oath originally stated in part: “I will follow that system of regimen which, according to my ability and judgment, I consider for the benefit of my patients, and abstain from whatever is deleterious and mischievous. (...) I will give no deadly medicine to any one if asked, nor suggest any such counsel; and in like manner I will not give to a woman a pessary to produce abortion.” Hippocrates saw abortion as being in direct opposition to a doctor's role of promoting life and health.
Physicians who practice abortion today do not obey this Oath in its original formulation but this should not worry Christian doctors as the original wording began I swear by Apollo, Æsculapius, Hygieia, and Panacea which are Mythical Greek gods.