A primary key is used as a unique, indexed identifier into a table. Likewise, a DNA sequence indexes and identifies a unique human being. That's the only definition that suffices in the physical realm to disambiguate one human from another.
The proper question to be asking is, given our obligation to our fellow man (assuming you, as a Pelagian, accept any such obligation), should we be taking on these activities that produce human life in the first place? Why wag the dog?
The only way out of this moral delimma is to ban invitro fertilization. Then there will be no empryos to cry over. There will be childless couples who have been denied a chance to become parents becuase of someone else’s desire to control the moral decisions of others.
Where in the pro-life movement is anyone demanding an end to invitro?