The U.S. Supreme Court has rejected Arizona's attempt to ban most abortions after 20 weeks of pregnancy.
The decision doesn't disturb most of the similar prohibitions that other states have on the books.
The justices on Monday declined to reconsider a lower court ruling that says the law violates 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.
Gov. Jan Brewer signed the ban into law in April 2012. Nine other states have enacted similar bans starting at 20 weeks or even earlier.
The 9th U.S. Circuit Court of Appeals last year said such bans violate a long string of Supreme Court rulings starting with the landmark Roe v. Wade decision in 1973.
However, most other states' 20-week bans haven't been challenged in court, and the 9th Circuit's ruling is binding only in its nine-state territory, which also includes Idaho.
Other states with 20-week bans include Alabama, Arkansas, Georgia, Idaho, Indiana, Kansas, Louisiana, Nebraska, North Carolina, North Dakota, Oklahoma and Texas.
Supporters of the Arizona ban argued that it protected women's health and prevented fetuses from experiencing pain. Whether fetuses can feel pain before viability is disputed.
Supporters of the Arizona ban expressed disappointment, frustration and determination.
"Often it takes multiple times before the U.S. Supreme Court will take an issue," said Cathi Herod, president of the Center for Arizona Policy. "This fight is far, far from over."
Other states' bans generally haven't been challenged because there weren't doctors whose practices would be affected and who were willing to fight the issue in court, said Janet Crepps, a lawyer for the Center for Reproductive Rights.