SAN FRANCISCO - Federal appellate judges on Monday picked apart legal arguments by Maricopa County Attorney Bill Montgomery on why Arizona can ban abortions for most women at 20 weeks.

Montgomery sought to convince a three-judge panel of the 9th U.S. Circuit Court of Appeals that "new medical evidence" of increased risk of the procedure at that point, coupled with other new evidence a fetus at that point can feel pain, entitles state lawmakers to conclude the procedure should be off-limits at 20 weeks and beyond, except to save the mother's life or significant harm.

But Judge Andrew Kleinfeld said U.S. Supreme Court rulings, going back to 1973, make it clear that both are legally irrelevant when it comes to the rights of women to terminate a pregnancy prior to viability, the point at which a fetus can live outside the womb. That is generally considered to be between 22 and 24 weeks.

"There is no right to an unsafe abortion," Montgomery responded.

Kleinfeld said that may be the law at some point in the future. But the judge said as long as the Supreme Court has said the risk to the mother of a pre-viability abortion does not trump her choice, then the appeals court has no choice but to declare the Arizona law invalid.

Judge Marsha Berzon also questioned Montgomery's arguments about new evidence. She said the Supreme Court "perfectly understood" that the later an abortion is performed, the greater the risk to the mother.

"Ordinarily, one gives people the right to make medical decisions, including the risk to themselves, as long as they're told what the risks are," she said.

And Kleinfeld said the relative risks do not matter.

"People decide to have dangerous, even foolishly dangerous medical procedures done on themselves all the time," he told Montgomery.

"Sometimes they have to shop around for a doctor because it's such a stupid idea," Kleinfeld continued. "But they still have a right to do it."

Judge Mary Schroeder also pointed out that the Supreme Court already has dealt with the question of the risk to the mother. She said that's why the high court has upheld various laws to regulate abortion, including requiring women be informed of the potential dangers of the procedure.

Montgomery is hanging his legal hat on a 2007 Supreme Court ruling known as Gonzales that upheld a federal law outlawing "partial birth" abortions, even if performed prior to viability. That procedure involves partially delivering a baby before killing it.

But Janet Creps of the Center for Reproductive Rights argued - and Kleinfeld appeared to agree - the high court was solely outlawing one type of abortion and not all abortions.

Montgomery responded that if the high court could find partial-birth abortions unacceptable, even without testimony on fetal pain, then it could easily uphold the Arizona law based on the new evidence legislators considered.

State Solicitor General David Cole, also defending the law, appeared to fare no better with a more technical argument that the two doctors challenging the law have no standing to sue. Only a woman denied an abortion at or after 20 weeks of pregnancy has that right, he contended.

That brought raised eyebrows from Kleinfeld. He asked how a woman at 20 weeks of pregnancy could bring a full-blown court challenge and get a ruling in the few weeks before viability.

"With all due respect, that's the woman's problem," Cole responded. "She could have made that decision at an earlier time."

But Kleinfeld said there are some serious fetal medical conditions that cannot be diagnosed before 20 weeks. And the judge was not sure it makes sense to deny a woman the right to abort a fetus at that point, even if it does feel pain.

"He'll have one operation after another and then will die … basically be born into hell and die," the judge said of children with severe abnormalities.

Montgomery conceded after the hearing that this is unlikely to be the last stop in his legal battle, that if the appeals court rules against him he could try to take his case to the U.S. Supreme Court.

The 9th Circuit judges gave no indication when they will rule. Until they do, the court has blocked the state from enforcing its provisions.

"Ordinarily, one gives people the right to make medical decisions, including the risk to themselves, as long as they're told what the risks are."

Judge Marsha Berzon, 9th Circuit Court of Appeals