An appeal regarding the availability of the abortion pill is currently underway, and the Supreme Court will be making a decision on the matter.

The US Supreme Court is set to make a critical decision on Wednesday about the future of mifepristone, a drug that is used in more than half of all abortions in the United States. The Biden administration has filed an emergency application with the Court seeking to maintain the Food and Drug Administration’s (FDA) approval of the drug. The FDA had approved the drug over two decades ago, but a legal challenge initiated by anti-abortion groups is now calling for its approval to be invalidated.

The legal dispute began last November in Texas when anti-abortion medical groups sued the FDA, claiming that the agency had not followed the correct procedures when approving the drug. They further alleged that the agency had ignored the dangers associated with the drug over the years. A federal judge in Texas, Matthew J. Kacsmaryk, issued a preliminary ruling earlier this month that invalidated the FDA’s approval of the drug. Judge Kacsmaryk is a known opponent of abortion and had referred to abortion providers as “abortionists” in his ruling.

However, a federal judge in Washington state, Thomas O. Rice, issued a contradictory ruling in a separate lawsuit, blocking the FDA from limiting the availability of mifepristone in many parts of the country. The Biden administration immediately appealed Judge Kacsmaryk’s ruling, and a three-judge panel of the US Court of Appeals for the Fifth Circuit announced that the drug could remain legal and available while the lawsuit progresses through the courts.

The conflicting rulings in different parts of the country all but ensured that the case would be brought before the Supreme Court. The Biden administration has asked the Court to pause the appeals court ruling that sought to limit access to the pill, arguing that such a decision would have far-reaching consequences beyond abortion pill access.

Mifepristone is usually used in combination with a second drug, misoprostol, during the first 10 weeks of pregnancy. The first drug blocks progesterone, a hormone that enables a pregnancy to develop, and the second drug, taken one or two days later, causes contractions and helps the uterus expel its contents.

The legal battle over mifepristone comes after the Supreme Court overturned the constitutional right to an abortion last year. Since then, political and legal conflicts have centered on medications used in the procedure, with lawmakers in some conservative states targeting abortion pills.