I'm a doctor who helped pave the way for legal abortion. We can't return to the days of botched back-alley operations.

• Dr. Barbara H. Roberts saw the effect of back-alley abortions before Roe v Wade passed in 1973.
• She learned how to perform abortions as a medical resident and became an advocate for legalization.

This as-told-to essay is based on a conversation with Barbara Roberts. It has been edited for length and clarity.

While I was a medical student in the late 1960s and early 1970s, I witnessed the horrible results of laws that prohibited abortion. I witnessed women coming into the emergency room in septic shock, with perforated wombs, and even partially disemboweled because they were desperate enough to put themselves in the hands of back-alley abortionists.

Once, we admitted a woman who had had an illegal abortion, as most abortions were in those days. A foot of black, gangrenous bowel was hanging out of her vagina, mute testimony both to her desperation and to the ignorance and brutality of whoever had butchered her. With a hysterectomy and bowel resection she survived, but barely.

Another day, standing in line in the cafeteria, I overheard two gynecology residents discussing a consultation on a pregnant patient who had been admitted to a medical floor. An alcoholic, she had cirrhosis of the liver and was already the mother of several children. She also had rheumatic heart disease, and one of her deformed valves was infected and severely leaky.

The doctors on the medical service had consulted the gynecology service, requesting that their patient be given a therapeutic abortion. They were certain that the stress of pregnancy would exacerbate her heart condition, perhaps fatally. The gynecology residents, both Catholic, were discussing how to make sure this patient's case was presented to one of the Catholic attending doctors so that the therapeutic abortion would be denied.

Incensed, I reported what I had heard to Dr. Dorothy Hicks, the only female attending ob-gyn. I suspected, correctly, that she would agree abortion was indicated. We were unable to find out the name of the patient, and months later, after I had returned to Cleveland, Dr. Hicks wrote to tell me that the patient had been readmitted with intractable heart failure late in her pregnancy and had died.

I was horrified, deeply angry, inexpressibly sad, and felt guilty.

I should have tried harder to find out who she was. I felt that I was just as responsible for her death as the residents. To this day, I regret not searching for her and obtaining the abortion that might have saved her life.

In time, these experiences gave birth to the anger and passion I would unleash in my work to legalize abortion.

I learned to perform abortions as a medical resident

That's what led me to become active in the pro-choice movement before January 22, 1973, when the Supreme Court passed Roe v. Wade. I learned how to perform abortions and helped found the Women's National Abortion Action Coalition.

I then went on to perform abortions at the Preterm Clinic in Washington, DC, which had legalized abortion before Roe v. Wade. Later, when I moved to Rhode Island to practice cardiology, I performed abortions at the local Planned Parenthood clinic.

I know what will happen now that Roe v. Wade has been overturned

I was overcome with sadness and rage when Roe v. Wade was overturned in June. People will die because of this decision. I've seen it happen.

The struggle for abortion rights is crucial to allowing women to control their bodies and their fates. The fetus is no more a human being than an acorn is an oak. But even if the fetus, or to use the old Catholic teaching, the sperm itself, was undeniably human, abortion should still be legal because no human being's right to life includes the right to use another person's body, or any part of it, without that person's consent — not their kidney, cornea, a graft of skin, nor a pint of his blood. Yet anti-abortion laws give a fetus the right to occupy an unwilling person's uterus — which affects every major organ system in her body — without her consent.

Now, we must mobilize. We must educate people about the devastating effects of unwanted pregnancy.

History will repeat itself if we don't. We can't go back.

Barbara Roberts is a clinical associate professor emerita at the Warren Alpert Medical School at Brown University, a cardiologist, and the author of "The Truth About Statins, How to Keep From Breaking Your Heart: What Every Woman Needs to Know About Cardiovascular Disease" and "The Doctor Broad: A Mafia Love Story."