In some historical cultures, they did assert that a child is just something their parents (or more commonly just their father) came up with, and consequently they could use or dispose of as they pleased
But our moral traditions, several thousand years old, reject that idea, and distinguishing giving birth to something from designing it. (Did you never wonder what all that history with Arianism was about? Maybe you just assumed they argued about something which made no sense just because they were religious?)
You're just acting in accordance with the program already in you in procreating, it's not fully your own choice, and thus your child is on the same level as you.
> If you think something man made can
It was never about "can". It's about "should". And trying to wrap yourself in the white coat of science and rationality still won't let you derive a "should" without a "should" as input.
But now it's your time to give answers. As I said, giving personhood to our creations would obviously make a joke out of utilitarianism (and also any other moral philosophy, for that matter). So why exactly should we entertain your idea that we should? It undermines itself.