Voters in Colorado rejected an anti-abortion ballot measure on Tuesday that would have granted personhood rights to developing fetuses from the moment of fertilization.

The ballot measure, known as Amendment 67, would have amended the state's criminal code to include fetuses in the category of "human" and "child." Supporters of the measure said it would have more harshly prosecuted someone who caused a pregnant woman to lose her baby in a situation like a drunk driving accident.

Opponents warned that it also would have criminalized women who have abortions, without exception for rape or incest.

Colorado voters rejected the amendment by a vote of 63 percent to 37 percent -- the third time they have voted down a personhood measure in the past few years.

“For the third time, Colorado voters have said loud and clear: We don’t want extremists interfering in our personal and private decisions, and we won’t stand for attempts to ban abortion," said Jennifer Dalven, director of the American Civil Liberties Union Reproductive Freedom Project. "This isn’t surprising: Voters in Mississippi, South Dakota, Florida and other states defeated attempts to curb access to safe, legal abortion. Time and time again, Americans have shown that they support a woman’s right to make the best decision for herself and her family.”

Colorado voters on Tuesday did, however, elect to the Senate Republican Cory Gardner, who co-sponsored fetal personhood legislation in the House of Representatives.

North Dakota voters on Tuesday also rejected a personhood ballot measure by a margin of 64 percent to 36 percent. The measure would have amended the state constitution to say, "The inalienable right to life of every human being at any stage of development must be recognized and protected.'"

Supporters of the measure said it was not, in fact, a personhood bill and that it was only a statement of anti-abortion values. Opponents argued that the measure was so vaguely written, it could have been interpreted to ban all abortions without exception and even complicate the legality of some forms of birth control and in vitro fertilization.

Reproductive rights groups applauded the amendment's defeat.