Life as she knows it, the life she loves, is a product of that decision, she told me. “That’s not uncommon,” she said, adding that many athletes have similar stories.

In May, the Supreme Court announced it would hear Mississippi’s appeal of a lower court’s decision that blocked the state’s law banning abortion after 15 weeks. In the Roe decision, the Supreme Court legalized abortion up to the time of fetal viability, roughly 25 weeks. Roe recognized that deciding whether to continue a pregnancy, which impacts a woman’s well-being and future, is a matter of individual choice.

Abortion rights activists believe that if the justices decide in favor of the Mississippi ban, the Roe decision will be severely hobbled. It is unclear how many women in sports oppose abortion rights, but this much is certain: The threat to Roe incensed and mobilized female athletes who want it protected. The 73-page brief, one of dozens of friend of the court briefs filed in the case, is meant as a show of support for the right to choose. Submitted last week by the high-powered law firm Boies Schiller Flexner, the brief is another sign of the fast-paced growth of athlete empowerment. Energized to speak out on issues far beyond their sports, they are networking as never before.

Perham, for example, found out about the brief only two weeks ago from Casey Legler, an outspoken former Olympic swimmer who is now a writer and restaurateur in New York.

“It was like this wild root system that we didn’t even know was there,” Legler said. “It was swimmers calling soccer players calling their agent who called the basketball player whose girlfriend is on the diving team who remembers the kid who played hockey.”

“We all know what’s at stake,” she added.

On Dec. 1, the Supreme Court is set to hear arguments in the Mississippi case, with a decision possible in the summer.

No matter what happens — and with a conservative majority on the court, but also a couple of swing justices, there is anxiety on both sides how it might rule — more than 500 female athletes have made themselves clear.