Pro-abortion activists are stepping up protests against a ballot measure to add “unborn human beings” to Colorado’s criminal code. Rallies were planned Friday at the Auraria Campus in downtown Denver and in Pueblo Saturday. Abortion opponents say Amendment 67 would strengthen protections for pregnant women. They argue that the language would increase existing penalties for crimes that injure or kill babies in the womb. But the measure doesn’t define “unborn human being,” leading reproductive-health activists to fear its adoption could outlaw abortion with no exceptions. They say it could also outlaw common fertility treatments in which fertilized embryos are destroyed.