LAS VEGAS — An emotional battle to define life as beginning at conception while banning abortions and limiting birth control gained new life Monday when a judge gave a group the OK to collect signatures supporting a proposed constitutional amendment.

The ruling was a victory for anti-abortion proponents, who are now closer than ever to putting their beliefs to a statewide vote in November. But it also raised questions about whether anti-abortion activists are using misleading language to try to persuade voters to broaden the definition of a person.

In his decision, Carson City District Judge James Wilson slammed the Nevada Prolife Coalition for inadequately describing the impact of defining a person as "every human being at all stages of biological development before birth."

He ordered that the measure be rewritten to note all potential ramifications of the proposed constitutional change, including restrictions on common birth control methods, in vitro fertilization treatment and embryonic stem cell research.

Proponents of the ballot measure called the ruling an unprecedented victory for Nevada voters, while threatening to appeal the required language revision.

Chet Gallagher, director of the Nevada Prolife Coalition, said "it's just not true," that the measure would limit birth control or in vitro fertilization treatment. Gallagher sits on the board of Personhood USA, a national group based in Denver that has unsuccessfully put similar measures before voters in Mississippi and Colorado.

"We believe moving from regulating abortion to eliminating abortion is the premier civil rights issue of our generation," he said. "Personhood will be a reality and we pray this will happen soon in the United States and in Nevada."

The Nevada Prolife Coalition must collect more than 72,000 signatures by June to get the measure on the 2012 ballot. The measure would prevent all abortions, including situations involving rape, incest or the mother's health.

The court ruling came a month after the movement flamed out in Mississippi, with 58 percent of voters there rejecting a proposed state constitutional amendment to give fetuses the same rights as people. Mississippi has some of the nation's toughest abortion regulations, but opponents of the measure successfully stressed that it would limit birth control.

Supporters, however, seemed to have been strengthened by the loss. They are pushing similar measures for state ballots in California, Colorado, Virginia, Oklahoma, Florida and Montana in 2012.

In Nevada, opponents said they will continue to fight the measure and could appeal to the Nevada Supreme Court. They had called on Wilson to declare the measure misleading and illegal.

Wilson said in his ruling that the measure was valid because it dealt with a single subject.

Elisa Cafferata, president and chief executive of Nevada Advocates for Planned Parenthood Affiliates in Reno, said the ruling was not a complete loss.

"They were trying to mislead the voters and at least the judge said you can't do that," she said. "Our main concern has always been that it was intentionally misleading."

Pam Caylor, president of the Nevada Prolife Coalition, said the group did its best to describe the measure in a few words. She said Nevada voters are well positioned to turn the measure into law, despite recent losses in other, more conservative states.

"It is time to protect every person that is a person in the United States," she said.

An unrelated group called Personhood Nevada is also trying to persuade Nevada voters to outlaw abortion in 2012. Their measure would add seven words to the state constitution: "The term 'person' includes every human being."

The measure is also being challenged by Planned Parenthood, and court arguments are slated for Wednesday. A ruling is expected next week.

This is the closest anti-abortion activists have gotten to qualifying an anti-abortion measure on the statewide ballot.

In January 2010, District Judge James Todd Russell in Carson City ruled a similar initiative was too general and vague, would affect constitutional rights to life, and could reshape state criminal law, among other implications.

Don Nelson, president of Nevada Life in Sparks, said he supports the idea of defining life as beginning at conception, but called such ballot measures a waste of time at best. At worst, he was concerned an initiative could end up before the U.S. Supreme Court and result in a ruling that would strengthen Roe v. Wade, the decision that legalized abortion.

"We don't see this as the best strategy," he said. "We think it could in fact harm the pro-life movement."