The Supreme Court decided to let stand a ruling blocking an Arizona abortion law. (Karen Bleier/AFP/Getty Images)

The Supreme Court on Monday declined to review a lower court decision blocking an Arizona law that abortion-rights supporters said would have virtually eliminated medical abortions in the state.

Arizona said the new restrictions in the law were meant to protect women’s health. But the groups challenging the law said it would make it extremely difficult for some women to obtain medical abortions, which are used in the earliest stages of pregnancy.

The U.S. Court of Appeals for the 9th Circuit blocked the law while it was being challenged. Similar laws are in effect in Ohio and Texas, and such restrictions are increasingly being enacted at the state level.

“The court did the right thing today, but this dangerous and misguided law should never have passed in the first place,” Cecile Richards, president of Planned Parenthood Federation of America, said in a statement after the court’s action. “Politicians across the country should take note: These harmful and unconstitutional restrictions won’t be tolerated by the courts or the public.”

Arizona’s restrictions would ban women from taking the most common abortion-inducing drug, mifepristone, after the seventh week of pregnancy. The state says the measure is consistent with what the Food and Drug Administration mandated when it approved the drug in 2000. Mifepristone is prescribed along with a second drug, misoprostol.

But since the FDA’s initial approval, doctors have found that mifepristone is effective in much smaller doses that are beneficial to women and can be used for an additional two weeks into the pregnancy, challengers to the law said.

The Arizona law said that the drugs had to be taken at the levels the FDA approved in 2000 and that they needed to be administered in clinics. The challengers had said the second drug may be taken at home.

Arizona had claimed that its intentions were only to protect women from the possible side effects of the drugs used in the procedure, which it said have been found to present “significant medical risks to women because of possible infection, sepsis, and hemorrhaging.”

The law does not affect surgical abortions. Planned Parenthood said medical abortions account for about 40 percent of the first-trimester abortions performed at its clinics.

The legal issue in the case is whether Arizona’s law imposes an “undue burden” on women seeking abortions before the point of fetal viability. That is the standard the Supreme Court set in a 1992 decision, and the legal battle over abortion since then has focused on when abortion regulations — which are increasing in states with Republican-led legislatures — cross that line.

As is customary, the court did not give its reasons for declining to review the decision of the 9th Circuit. Because of the legal challenges, the Arizona law has yet to be enforced.

The case is Humble v. Planned Parenthood of Arizona.