PHOENIX -- The U.S. Supreme Court is being asked to review a federal appeals court ruling that Arizona's law banning abortions after the 20th week of pregnancy is unconstitutional.
Maricopa County Attorney Bill Montgomery filed a petition Friday with the high court. He argued on the Arizona law's behalf in front of the 9th U.S. Circuit Court of Appeals in San Francisco last November.
The three-judge panel ruled in May that Arizona's abortion law is clearly in conflict with Roe v. Wade.
The federal appeals court said the state's law violated a woman's constitutionally-protected right to terminate a pregnancy before a fetus is able to survive outside the womb.
"Viability" of a fetus is generally considered to start at 24 weeks. Normal pregnancies run about 40 weeks.
The Arizona law seeks to push back the last possible date, banning abortions past 20 weeks, even in situations where the doctor discovers the fetus has a fatal defect.
When the law was first challenged in federal court by the American Civil Liberties Union and the Center for Reproductive Rights on behalf of three Arizona obstetrician-gynecologists, a U.S. District Court judge ruled that it was a regulation, not a ban, and therefore constitutional.
Arizona Gov. Jan Brewer signed the ban into law in April 2012 after it was approved by the Republican-led Legislature.
Supporters said the law was meant to protect the mother's health and prevent fetuses from feeling pain. U.S. District Judge James Teilborg ruled it was constitutional, partly because of those concerns, but the 9th Circuit blocked the ban from going into effect until it ruled.
Lawyers representing Arizona argued that the ban wasn't technically a law but rather a medical regulation because it allowed for doctors to perform abortions in medical emergencies.
At least nine other states have enacted similar bans starting at 20 weeks or even earlier. Several of those bans had previously been placed on hold or struck down by other courts.