I reject the premise that its about sanctity of human life, if that was the case this folks will be ardently against the death penalty which multiple studies have shown have sent innocent folks to be executed as punishment, one innocent life lost alone for a crime not committed as a disgrace.
Its about control. The moment this kids are born same conservatives want to cut welfare programs, school lunch programs, defund schools, they want to make it harder to receiver social benefits, they basically turn the child destitute or a high degree of being because the will be in poverty.