More than six in 10 of the abortions in the U.S. last year were done through medication, up from 53% in 2020, new research shows.

The Guttmacher Institute, a research group that supports abortion rights, said about 642,700 medication abortions took place in the first full calendar year after the U.S. Supreme Court overturned Roe v. Wade. Medication abortion accounted for 63% of abortions in the formal health care system.

The data was released Tuesday, a week before the high court will hear arguments in a case that could impact how women get access to the drug mifepristone, which is usually used with another pill in medication abortions.

The Food and Drug Administration approved mifepristone for abortions in 2000, deeming it a safe and effective way to terminate an unwanted pregnancy. In early March, CVS and Walgreens, the two largest pharmacy chains in the nation, said they planned to make the medication available to patients as soon as within the month. Both pharmacies told CBS News they had become certified to dispense the pills following regulatory changes the FDA made last year that allow retail pharmacies to sell the pills.

The pharmacies’ moves, which came at a time when abortion access has been restricted across parts of the U.S., drew praise from President Biden.  

“The stakes could not be higher for women across America,” Mr. Biden said in a statement earlier this month. “I encourage all pharmacies that want to pursue this option to seek certification.”

The nationwide swing toward abortion pills over surgery has caused anti-abortion rights advocates to sue the FDA over the drug’s approval and to stage protests outside of pharmacies. 

Addressing Tuesday’s statistics, Guttmacher researcher Rachel Jones said the increase wasn’t a surprise.

“For example, it is now possible in some states, at least for health care providers, to mail mifepristone to people in their homes,” Jones said, “so that saves patients travel costs and taking time off work.”

Guttmacher’s data, which is collected by contacting abortion providers, doesn’t count self-managed medication abortions that take place outside the health care system, or abortion medication mailed to people in states with abortion bans.

Dr. Grace Ferguson, an OB-GYN and abortion provider in Pittsburgh who isn’t involved with the research, said the COVID-19 pandemic and the overturning of Roe v. Wade “really opened the doors” for medication abortions done through telehealth.

Ferguson said “telehealth was a really good way of accommodating that increased volume” in states where abortion remained legal and saw an increase in people who traveled from more restrictive states.

Guttmacher data shows that medication abortions have risen steadily since mifepristone was approved by the Food and Drug Administration in 2000. The drug, which blocks the hormone progesterone, also primes the uterus to respond to the contraction-causing effect of another drug, misoprostol. The two-drug regimen is used to end a pregnancy through 10 weeks gestation.

The case in front of the Supreme Court could cut off access to mifepristone by mail and impose other restrictions, even in states where abortion remains legal.

The new research came days after Vice President Kamala Harris visited a Minnesota women’s reproductive health clinic that performs abortion services. Her office said it was the first time that either a sitting president or vice president has visited a reproductive health clinic.