"Arizona simply cannot proscribe a woman from choosing to obtain an abortion before the fetus is viable," the court wrote.
Several states have pursued or passed aggressive limits similar to the Arizona law. North Dakota has banned abortion after six weeks of pregnancy — the most restrictive law in the country.
Abortion-rights supporters praised Tuesday's ruling. They have also challenged other states' abortion restrictions in the courts.
“Today’s decision is a huge victory in the fight to protect women’s fundamental reproductive rights, and it should send a clear message to anti-choice politicians that their attempts to deprive pregnant women of critical health care are clearly unconstitutional and will not hold up in court," said Sally Northup, president of the Center for Reproductive Rights.