This is a really neat topic. I have often wondered at what point the z/e/f becomes a real person. If one believed ina soul, then I guess it would be safe to assume that the z/e/f gains personhood at this time. Many cultures believe that the birth cry is the shock of the soul entering the body of the newborn. I was aware of the uniqueness of my children prior to their births, but I can't exactly tell you how I knew of them or when it occurred. I do remember it being fairly late in the pregnancy, say after 6 months or so. I believe that souls are somewhat eternal and go through many life cycles before they are absorbed back into the greater cosmos from which they came. This is probably why abortion and euthanasia are not negative events to me. I assume that all souls visit this earth again.
Let me tell you a story. My grandfather meant the world to me and I am pretty sure i meant the world to him. I have seen him many times since his death. Once, I moved out of a basement apartment a week early than I needed to because I just felt pressured to get out. The day I finished moving as I was driving across town, I swear i saw him driving in front of me. The next day we had a huge flood and the apartment I was living in was filled with 7 feet of water. Also, I believe he used to visit my house often, and I would come home frequently to the smell of Bel Air Cigarettes burning in my bathroom. It was comforting, in a way to think he was looking out for me. Some time before Hannah was born, his visits ceased and I haven't seen him since. Ironically enough, her little personality is cantankerous just like his was and she's even bowl legged like he was. Did his soul enter her? I really don't know. But I do remember having a day dream of lying with her ina translucent white oval shaped sort of bubble after a yoga class one day. I was comforted by this vision and felt safe inside of our protective shield. It was this moment that i first felt her as an individual.
Does this answer the question? Probably not, but it was very interesting to ponder. Thanks for bringing this up!