As an embryo, you have DNA and you can see the genetics of whether it will be male or female.

Agreed, but it cannot survive on its own. It requires a physically connected host. That's what I'm pointing out as the main difference between beheading an infant and an abortion in u/oldpatriot 's post.

Speaking of viability is just a leftist intellectual's way of moving the goalposts.

It's not moving the goalposts at all. It's pretty much exactly where the argument starts.