The Supreme Court on Monday said it won't rule on a case seeking limits on the abortion-inducing drug RU-486, leaving in place an Oklahoma court ruling that rejected a state law curbing the use of the so-called "abortion pill."

A 2011 Oklahoma law prevented doctors from "off label" use of the drug — a method preferred by doctors because it uses a lower dosage than what the Food and Drug Administration first approved 13 years ago. While the FDA hasn't officially approved the practice, it's common for the agency not to block off-label uses of drugs it has approved.

The Oklahoma Supreme Court struck down the law, and the state appealed to the U.S. Supreme Court, which agreed in June to take up the case.

But the nation's high court changed course and removed the case from its docket after the Oklalhoma court last week clarified its ruling, saying the law would not only limit drug-induced abortions but also effectively ban them altogether. The state court also noted off-label uses of drugs are standard medical practice.

In a one-sentence order, the U.S. Supreme Court explained its move by saying the case was "improvidently granted."

Oklahoma said its appeal was justified because at least eight women have died using the drug. More than 1.4 million women have taken the drugs to induce abortions.

Anti-abortion groups said the law is vital to ensure death tolls caused by the drug don't increase.

"This decision places women’s lives at risk while siding with an abortion industry bent on pushing women in and out of clinics quickly, without regard to their health or best interests," said Americans United for Life President Charmaine Yoest.

But abortion-rights groups praised the court's move, saying the law was nothing more than a blatant attack on women's rights disguised as a health issue.

"The Supreme Court has let stand a strong decision by the Oklahoma Supreme Court that recognized this law for what it is: an outright ban on a safe method of ending a pregnancy in its earliest stages," said Nancy Northup, president and chief executive of the Center for Reproductive Rights.