When pregnant, do you consider it a baby or a fetus until it is born?

My doctor and I was having a disagreement on this subject because he doesn't believe it a baby until it is born and breathing otherwise while still in the womb he considers it a fetus. So my question for the ones that believe it is a fetus until it is born and breathing then what do you call babies that are still born and never breathe a breath of air? I am sorry if this question offends anyone who has had still born babies, my sympathy goes out to you.