Colorado legislators have placed an amendment on voters' ballots that would extend legal rights to the unborn.

Amendment 67, known as the "personhood amendment," would change the state's constitution by defining the unborn as persons, and could effectively outlaw abortions, Fox reports.

The proposed legislation stems from the case of Heather Surovik, who was eight months pregnant when a drunk driver struck her car in July 2012.

"When she woke up in the hospital, she was told that her baby had not survived," Amendment 67 supporter Jennifer Mason told Fox News. "But not only that, there would be no charges filed in relation to his death because under Colorado law, he was not considered a person."

Surovik was devastated by the news. "They can't tell me that's not a baby," she said. "He was eight pounds, two ounces. Brady was the second victim, and nobody recognised it."

Opponents of Amendment 67 point out that abortions and some forms of birth control would be banned if voters approve the law.

"You end up giving legal and constitutional rights to a woman's fertilised egg and when you apply that definition to the criminal code and the wrongful death statute, you end up making criminals out of women and their doctors," "Vote NO 67" campaign manager Fofi Mendez explained.

After Surovik's tragic accident, unlawful termination of a pregnancy became a crime in Colorado. The legislation is not retroactive, however, and the drunk driver was not charged in the death of Brady.

Recent polls predict that Amendment 67 will not pass on Nov. 4, and no other state has "personhood" legislation in their constitution.

"It's gone down to overwhelming defeat on past occasions," political analyst Eric Sonderman said.