Let's go back to how insanely ridiculous your original argument is
"if you like slavery then I can understand why you don't like or understand the constitution."
You think I like slavery because I dislike a document that was authored by 19th century slaveowners? The Constitution of the United States does a lot more than simply limit the scope of powers of the federal government, it lays the foundation for the intrusive bourgeois government and capitalist mode of production to manifest.
You either debated someone who was being insincere with you or you are simply making up the 5 year old thing. That isn't remotely a mainstream argument by any measure. That's not even an abortion -- which by definition is the expulsion of a fetus from the uterus. Do you think children are in the womb for up to five years?
I think that abortions should be allowed so long as the embryo or fetus is inside of the womb. I justify this by saying that a person has a right to exert their authority over their own autonomy by refusing to carry a fetus to term. However, once a baby is born it is independent of the host and nobody has any right to terminate it. It is vital that so-called "late-term abortions" be allowed because they are necessary in a range of cases. Otherwise, second or third trimester abortions are the unfortunate product of pro-birther laws impinging on the ability to access an abortion more timely.