My wife lurks on the forums and wanted to post this.
First, congratulations to you and the missus. I'm all in favor of both open carry and concealed carry of children. To answer your questions from a maternal perspective: Yes. Deadly force is a much greater danger when a woman is pregnant. After two pregnancies, and now into my third, I can attest to the fact that a pregant woman, even one in good shape, is less maneuverable, or able to evade dangerous situations. Both unarmed force and armed force are problems. A simple fall would be unlikely to harm a baby, but the mother being pushed down a flight of stairs, or beaten, or blows to the abdomen can and have killed the unborn. For that matter, hazardous situations become accentuated during pregnancy: smoking, pollution, noise, stress—the list goes on and on. And some people think pregnant women are easy targets for purse-snatchings, robbery, and assault.
Regarding the duty to retreat, a father has to not only be aware of his own situation, but those under his care. When I am out walking with my young children in a stroller, I have to think not only of my own ability to escape, but whether I can safely retreat with them in tow.
In the case of People of the State of Michigan v. Kurr, (http://news.findlaw.com/hdocs/docs/abortion/mikurr10402opn.pdf
) this very issue of defense of others went to the courts. Kurr, a woman 17 weeks pregnant with quadruplets, stabbed and killed her boyfriend after he punched her in the stomach twice, lunging at her a third time. She stated she was never in fear of her own life. Kurr argued that she should be aquitted on the grounds that she acted in defense of others, her unborn babies. The trial court refused this defense, saying the babies were pre-viable. They concluded that for a defendant to assert a defense of others, there had "to be a living human being existing independent of the defendant." It stated forther, "even under the evidence in this case, under 22 weeks, there are no others." She appealed based on the jury flawed view of defense of others, and won. (Thank God!)
In Ohio, the Revised Code 2903.01 defines aggravated murder, murder, voluntary manslaughter, involuntary manslaughter, negligent homicide, aggravated vehicular homicide, aggravated vehicular assault, felonious assault, aggravated assault, assault, negligent assault. The law applies to a person which includes an "unborn member of the species homo sapiens
, who is or was carried in the womb of another."
The question of self-defense and defense of others seems to be settled now. Laci and Connor's law- Violence Against Unborn Children Act (http://news.findlaw.com/hdocs/docs/abortion/unbornbill32504.html
) is federal law. By that statute, "Whoever engages in conduct that...causes the death of, or bodily injury...to a child who is in uterto at the time the conduct takes place is guilty of a separate offense under this section. Except where otherwise provided in this paragraph, the punishment for that separate offense is the same as the punishment under Federal law for that conduct had that injury or death occured to the unborn child's mother."
So, the long and short of it is yes. Defense of others applies to the unborn, as well as the born, in most states. Check http://www.aul.org/UVV
for a current summary of similar laws between states. Congratulations again, and protect that bump well!