At everyday level - dismissing extra fertilized eggs is killing new life according to the "life-at-conception". And IVF, contraception, eggs freezing, etc. gives more power/freedom to women which is abomination to the conservative forces. And it isn't some utility level power/freedom like guns or speech, it is the most fundamental power domain for any biological life - the power to determine the genetic makeup of the next generation of the species.

At the deep biological level - the fundamental goal of pro-life policies is to enforce r-selection, ie. more random based, whereis pro-choice is K-selection, ie. more managed (https://en.wikipedia.org/wiki/R/K_selection_theory), and like the abortion the IVF, egg freezing, contraception, etc. are all enemies of r-selection while they are tools of K-selection.