A U.S. appeals court ruled Wednesday to restrict access to the abortion pill mifepristone, partially upholding a lower court ruling that alarmed abortion advocates and pharmaceutical companies.

The New Orleans-based 5th U.S. Circuit Court of Appeals ruled to block changes that made the drug more accessible, but reversed a lower court ruling that suspended the drug's approval in 2000.

Mifepristone's availability remains unchanged for now, following an emergency order from the U.S. Supreme Court in April preserving the status quo during the appeal.

The three-judge 5th Circuit panel was reviewing an order issued in April by U.S. District Court Judge Matthew Kacsmaryk in Amarillo, Texas. While it was a preliminary ruling that applied while the case was pending, Kacsmaryk said he was ultimately likely to make it permanent.

The ruling stems from a lawsuit brought by four anti-abortion groups headed by the recently formed Alliance for Hippocratic Medicine and four anti-abortion doctors who sued in November.

They contend the U.S. Food and Drug Administration used an improper process when it approved mifepristone in 2000 and did not adequately consider the drug's safety when used by minors.

All three judges on the panel are staunchly conservative, with a history of opposing abortion rights.

The decision will almost certainly be appealed first to the full 5th Circuit and then to the U.S. Supreme Court, which last year overturned its landmark Roe v. Wade ruling that had legalized abortion nationwide.

Since then, at least 15 of the 50 states have banned abortion outright while many others prohibit it after a certain length of pregnancy, according to the Guttmacher Institute, a research organization that supports abortion rights.

Mifepristone is part of a two-drug regimen with misoprostol used for medication abortions, which account for more than half of U.S. abortions. It is approved for use in the first 10 weeks of pregnancy.

Numerous medical studies and many years of real-world use have concluded that the drug is safe and effective.

Major medical associations, including the American College of Obstetricians and Gynecologists and the American Medical Association, have said in court filings that pulling mifepristone off the market would harm patients by forcing them to undergo more invasive surgical abortions.

Hundreds of biotech and pharmaceutical company executives have called or the reversal of Kacsmaryk's ruling, saying it ignores decades of scientific evidence on the drug's safety and undermines the FDA's authority, potentially creating chaos for the industry that relies on the agency.