I'm asserting that no human being born alive was not prior to birth, a human being inside a mother, but called a fetus.
Actually, first before there's even an embryo, there's a fertilized egg. It may or may not implant - independent of any action on the part of the mother to be. If it doesn't, that egg, a single cell, is swept away in the normal menstrual flow. Are you asserting this egg that failed to implant was a human being?
Some of the eggs that implant are grossly malformed, simply fail to multiply and eventually die. Are these deformed eggs human beings?
Some eggs, having successfully implanted and having gone through a number of cell divisions, fail to differentiate into different germ layers, the precursors of tissues and organs. They also fail to develop a placenta and umbilical chord. Thus, these collections of cells do not get nourished, but simply die. Are these collections of undifferentiated cells human beings?
There are also miscarriages that occur while the embryo is still not quite human in shape, and certainly has no brain. Are these miscarriages to be treated as human beings? Do they require a death certificate? Are they, in your view, damned to hell for eternity because of having never been baptized and being under the doom of original sin?
Please give specific answers to these questions.