The ratio of abortions carried out with medication rose to 63 percent between 2020 and 2023 in the United States, according to analysis published ahead of a Supreme Court hearing on restricting access to the pills.

The research made public Tuesday by the Guttmacher Institute, which campaigns for abortion rights, said that medication accounted for 63 percent of all US abortions last year -- an increase from 53 percent in 2020.

The use of medication -- rather than surgical procedures -- to terminate pregnancy has risen steadily since the Food and Drug Administration (FDA) approved the abortion drug mifepristone in the United States in 2000, the Guttmacher Institute said.

Next week the Supreme Court will hear arguments to reduce access to mifepristone, which is one of the most common types of abortion medication and can be obtained by patients via mail.

The hearing comes after a Louisiana appeals court ruled in August in a case brought by anti-abortion groups against the FDA that mail-order access to the drug should be banned and it should instead only be administered by a doctor.

The ruling, which was suspended pending the Supreme Court hearing on March 26, also reduced the legal time limit to use mifepristone from within 10 to seven weeks of pregnancy.

The Guttmacher Institute said the Supreme Court "will have to decide whether to ignore the FDA and reimpose unnecessary barriers to access or to respect the scientific evidence that mifepristone is safe and effective."

Earlier this month, two major American pharmacy chains, Walgreens and CVS, announced they would start filling mifepristone prescriptions in states where abortion remains legal, including New York and California.

It comes after the US Supreme Court overturned the nationwide right to abortion in 2022, allowing each state to pass its own laws governing the procedure.

Twenty-one states have since banned or moved to restrict abortions to limits tighter than before Roe v Wade, the 1973 case law that previously upheld the constitutional right to terminate a pregnancy.