Crissy Perham had never spoken publicly about her choice.

In 31 years, Perham, a three-time Olympic medalist, told only a handful of people what it was like to be pregnant as a struggling college sophomore and decide to have an abortion. She kept quiet about the freedom and the second chance that ending her pregnancy gave her. Kept quiet about how it helped pave the way for a swimming career and the success she experienced once it was over.

But now, she said, speaking up is a must.

“I’m 51, at the point where I shouldn’t be embarrassed about the decision I made for my reproductive health,” Perham told me in an interview last week. Nobody else, she continued, should have to feel ashamed and embarrassed to tell their stories either, as is so often the case. “Especially with so much on the line.”

I sought out Perham because she was one of more than 500 female athletes who filed a startling brief to the Supreme Court last week, a bold show of support for reproductive rights in a pending case that could lead to the dismantling of Roe v. Wade, the 48-year-old high court ruling that legalized abortion in every state.

An abridged version of Perham’s story, straightforward in its honesty, is told in the brief — which was backed by a wide cast that included little-known collegiate athletes, Olympians past and present, well-known stars such as Megan Rapinoe and Sue Bird, and the W.N.B.A. players’ union.

The brief’s primary claim? If women do not have the option of abortion, their lives could be disrupted and they will not thrive in sports at levels we’ve grown accustomed to — levels witnessed recently at the Tokyo Olympics, in the W.N.B.A. playoffs and the U.S. Open tennis tournament in New York. Having the ability to say when or whether to become mothers directly connects to a key ingredient that has fueled the broad success of women in high-level sports: the ability to control, nurture and push the body to its limits, without breaks of months or years, and without the sometimes permanent physical changes that pregnancy can cause.

In several discussions with me, Perham expanded on her story, opening up to a reporter for the first time about the tough decision she made when she was a 19-year-old swimmer at the University of Arizona.

She spoke of the waves of raw fear she felt upon finding that the birth control pill she had been taking failed. She remembered realizing she didn’t have the maturity to raise a child, nor the means. Deep in her bones, she knew having a baby would derail the athletic dreams that had defined her for years.

Some female athletes manage to have children and remain in the upper reaches of their sport. That’s terrific. Consider the flip side: the way that steering clear of motherhood, sometimes through abortion, keeps female athletes in the game and balanced in life.

For all sorts of reasons, perhaps the biggest being societal shame, it’s rare to hear from female athletes who have ended their pregnancies.

But Perham told me about driving alone through Tucson on a morning in January 1990 to a low-slung Planned Parenthood and being greeted by steady, nonjudgmental medical staff members who performed the abortion with care.

“Ending my pregnancy, I made a decision about which direction to take my life in,” she said. “Someone else might decide to go in another direction, and that’s fine. But this was the best decision for me.”

Going through that crisis matured her, she said, and helped her focus as never before in class and in the pool. Seven months later she won a national swimming title in the 100-meter butterfly. She went on to capture back-to-back N.C.A.A. titles in that event.

One year later, she repeated as champion. She had gone from being an athlete who, in her words, “wasn’t on anyone’s radar for the national team” to one of the best in the world.

At the 1992 Summer Olympics in Barcelona, Spain — newly married to her first husband and known then as Crissy Ahmann-Leighton — she was co-captain of the American women’s swim team, winning two gold medals in relay races and a silver in the 100-meter butterfly.

Looking back now, with the cushion of time, Perham cannot imagine the good parts of her life happening as they have if she’d had a baby at 19. Not just her career in the pool but also her successful second marriage, her jobs coaching high school swimmers and being the mother to two sons who are now in their 20s.

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.