It's not really surprising you describe birth as if it was sawing off a woman's arm that magically after severed becomes a living being. There is no biological difference whatsoever in the brain or the heart that occurs when the ambilical cord is cut. Individual personalities in twins, for example, can already be seen in the womb in their behavioral patterns.
Respiratory, circulatory, digestive/gastrointestinal, and immune systems all change radically in their functioning at birth - A review of some:
The change in respiration with the first breath includes draining or absorption of amniotic fluid that has filled the lungs before, and the lungs now work on their own to obtain oxygen. This is related to circulatory changes especially through the heart.
There is increased systemic arterial pressure which reverses the flow through the ductus arteriosus and the latter withers and closes, and the foramen ovale also closes, so fetal circulatory patterns disappear.
The immune system of the fetus is the opposite of the newborn - it does not protect the fetus at all, but rather keeps it open to everything. From the moment of birth, this openness is reversed so the system starts to work to protect the newborn.
The gastrointestinal system is not functioning fully until after birth.
At birth, the liver has new functions and the kidneys become able to maintain the body's fluid/electrolyte balance.
Fetal temperature regulation is a function of the pregnant woman: she maintains its homeostasis. But at birth, this changes - maintaining its own homeostasis, the newborn starts to burn off stores of fetal brown fat.
Correct me if I'm wrong, I could be thinking of someone else, but weren't you the one that is against post-viability abortions? If so, why? It's an inanimate object until the exact moment the cord is cut.
I never said that I was against post-viability abortions, but that I supported Roe v Wade in allowing states to ban abortion after viability except in cases of imminent threat to the woman's life and major health functions, though I would add serious fetal defects, even though it is possible that the health exception for the woman may cover most of those cases.
I never said the fetus was an inanimate object until the cord is cut. I said that, by virtue of its biological connection to the woman's body and dependence on that biological connection for life and growth, the fetus was not a separate human life. Birth is the separation of the fetus. The physiological changes that occur as the fetus comes out and is out, even before the cord is cut, make the biological connection unnecessary. The physiological systems all change - they function differently, and in the case of the heart, there are structural changes related to circulatory change, as noted above.
Wtf does that mean and how is that related to you wanting to kill a baby and I don't?
I don't think an embryo or fetus is a baby. I do think the aim of abortion is removal of the embryo or fetus, not the causing of its death, and that, prior to viability, abortion does not kill it, but rather results in its ceasing to receive life from the woman, so that it dies. The issue is not taking an embryo's life away from it, but ending the woman's continuously giving part of her life to an embryo that wouldn't have more life otherwise.
You, on the other hand, seem to believe that the blastocyst has its own life like a neonate and would therefore go on living if it were in a petri dish if just given oxygen-rich nutrient there, as if the woman merely provided such nutrient, and that is not the case. The blastocyst has a short natural life span that draws to its end until it implants and lives as a part of a larger organism.
The human male contribution to reproduction is to transform an ovum into a zygote that can grow into a morula and a blastocyst. But the human female contribution is not just to provide the ovum that can be thus transformed. It is also, in pregnancy, to sustain a blastocyst as part of a woman's body and grow it into a human organism that can be a human being/person.
I don't want to kill babies. But because this human female contribution of pregnancy involves a woman's own body, blood, and life growing into a human being what cannot otherwise become one, I think a woman should have a right to decide on the basis of conscience and reason whether or not she should allow her body, blood, and life to do that or continue to do that in each pregnancy she has.
I do not think that a bunch of strangers in a legislature should prevent the woman from deciding one way or the other, because it is not their bodies, their blood, and their life that are doing that. To me, the behavior of a person's body and life is supposed to be under the sovereign control of the mind capable of conscience and reason directly connected to them.
For the government to deprive someone of that control over her own body and life is like the government forcing a person's body and life to speak words he or she may or may not believe in, or to worship in a religion he or she may not believe in, or to perform an act that genuinely violates his or her conscience, on pain of going to prison. I don't want to live in or be a citizen of a country that does that to people. I think it's disgusting.