College students and abortion rights activists rally on the steps of the Texas Capitol in Austin on Feb. 26. The Supreme Court refused on June 29, to allow Texas to enforce restrictions that would force 10 abortion clinics to close. (Eric Gay/AP)

The notion that abortion harms women, emotionally or physically, animates some of the opposition to the procedure in the U.S. "While we find no reliable data to measure the phenomenon, it seems unexceptionable to conclude some women come to regret their choice to abort the infant life they once created and sustained," Supreme Court Justice Anthony Kennedy wrote in a 2007 decision upholding the federal ban on late-term abortions.

Anti-abortion Web sites publish first-person accounts written by women who say they've come to regret their abortions. Norma McCorvey, or "Jane Roe" in the famous Supreme Court case that guaranteed the right to the procedure, later joined the anti-abortion movement. And an advocacy group, Silent No More, represents women who have undergone abortion and later regretted it.

But a new University of California study published in the journal PLOS ONE suggests that these women's experiences are the exception, and not the norm. Researchers recruited 667 women having abortions at 30 facilities across the U.S. Half were terminating pregnancies within the first trimester, while the other half were having abortions that fell close to the gestational age limit at their respective facilities. For a period of three years, the researchers administered semiannual phone surveys to the groups of women to assess their negative and positive emotions related to the procedure, and to ask whether they regretted it.

What they found: "Women in this study overwhelmingly felt that the decision was the right one for them: At all time points over three years, 95% of participants reported abortion was the right decision," the authors write.

And they found no difference in post-abortion experiences between women who had early abortions and those who had late ones: "Notably, we found no differences in emotional trajectories or decision rightness between women having earlier versus later procedures."

They also found that women reported both positive (happiness, relief) and negative (anger, guilt, sadness) emotional responses to abortion, and that the intensity of both of these emotions declined over time: "[T]he feelings of relief and happiness experienced shortly after the abortion tended to subside, as did negative emotions," the authors write.

Naturally, the study has limitations. The sample size is on the small side, although the researchers note that the cohort of women who participated were demographically similar to women in the U.S. as a whole. And there may be some selection bias happening: Women who agree to speak with researchers about their abortions may be different from women who decline, and their assessments of the procedure after the fact may differ as well.

Still, the study deserves note because of the uniformity of the responses. And it highlights a fact that often gets overlooked in the abortion debate: Experiencing negative emotions after an abortion is not the same thing as regretting it. The study shows that those negative emotions fade, and the overwhelming majority of women say that their abortion was the right decision, even three years after the fact.