Few issues have left Americans as deeply splintered as abortion. The debate encompasses countless philosophical, religious and legal questions about when life begins, the rights of a fetus and the legal authority of a woman to choose what to do with her body.

But in the Texas legislature in 2011 and 2013, when measures were enacted that imposed new regulations on where, when and how to get an abortion, the focus was on one simple idea: that abortion can be dangerous to a woman's physical and mental health.

Proponents of the law -- which requires the procedure to be done in "ambulatory surgical centers" regulated like hospitals -- argued that they were protecting women from unsafe conditions at abortion clinics. Critics said that argument was disingenuous and that the measures were instead designed to make it nearly impossible to operate an abortion practice, forcing many to shut down.

As a result, many women seeking abortions have had to travel long distances, wait for weeks and pay more -- barriers that might discourage them from choosing to terminate their pregnancies.

In the biggest case in a quarter-century on the topic, the U.S. Supreme Court considered whether the new measures were constitutional or whether they placed an undue burden on women seeking abortion. In Monday's opinion, the justices overturned Texas's abortion restrictions 5 to 3. The decision could have a ripple effect in other states across the nation.

As the Texas case made its way through the federal courts over the years, numerous misunderstandings and pure fiction about the health risks of abortion entered the debate. Among them were claims that the procedure is fraught with complications, causes cancer, leads to reduced fertility and results in depression, or even suicide.

One of the most critical questions the Supreme Court had to address was whether courts need to consider scientific evidence supporting the laws. A lower court said they do not. But there was a lot for the justices to look at in the medical literature.

The most important thing to know is that a number of recent analyses have dispelled the notion that abortion is unsafe as practiced now, legally in the United States. (Abortion in the past and in other countries is a different story.)

A key study published in the journal Obstetrics & Gynecology estimated that the risk of a woman dying after childbirth was 10 times greater than after an abortion. The study estimated that between 1998 and 2005, one woman died in childbirth for every 11,000 babies born. That compares with one in 167,000 women who died of abortion complications. Doctors who perform abortions say the most common complications are not bladder issues or problems with reproductive organs -- as some abortion opponents like to emphasize -- but mild infection that can be easily treated.

This study and others with similar conclusions come under fire from anti-abortion groups. Donna Harrison from the American Association of Pro-Life Obstetricians and Gynecologists told HealthDay News at the time that the findings are “speculation.” She argued that abortion mortality data are not systematically collected, which is true and important to keep in mind, but the evidence to date does not support the idea that abortion in the United States today is unsafe. Rather, it shows the opposite.

In fact, a 2014 study in the journal Contraception found that the safety of induced abortion as practiced in this country for the preceding decade looked very high compared with other procedures such as plastic surgery and dentistry and even activities such as biking and running marathons. One of the co-authors worked for the Center for Reproductive Rights, which advocates the right of women to choose abortion.

Below is a look at a chart from that study. (Tip: It looks as if you may want to avoid dental procedures in Illinois.)

Some anti-abortion groups also claim women who get abortions may have higher rates of breast cancer later in life. They note as evidence the fact that breast cancer has risen by 50 percent in the United States since abortion became legal through the 1973 Roe v. Wade decision. But even Abortion Facts. a website opposed to the procedure, notes that's hardly conclusive.

David Robert Grimes, a cancer researcher at Oxford University, wrote last year in the Guardian that this is "absolute unbridled nonsense of the highest order." "This alleged link is not supported by the scientific literature, and the ostensible link between breast cancer and induced abortion is explicitly rejected by the medical community," he said.

Another highly cited possible health issue related to abortion is something known as post-abortion syndrome. The term created public alarm when it was used decades ago by Vincent Rue, a therapist who testified before Congress on the issue in 1981. Numerous studies were commissioned to look into the topic. But by 1992, after systematic reviews of those studies, many doctors concluded there was no such link.

Writing that year in the Journal of the American Medical Association, psychiatrist Nada Stotland stated:

"This is an article about a medical syndrome that does not exist. A so-called abortion trauma syndrome has been described in written material and on television and radio programs. For example, leaflets warning of deleterious physical and emotional consequences of abortion have been distributed on the streets of cities in the United States. Women who have undergone induced abortion are said to suffer an "abortion trauma syndrome" or "postabortion trauma" that will cause long-term damage to their health…. [But] this assertion is not borne out by the literature: the vast majority of women tolerate abortion without psychiatric sequelae.”

Women often experience strong feelings after an abortion, but a study from the University of California at San Francisco found that one of their main emotions was relief. And even those who have negative emotions related to the procedure do not think they made the wrong decision. Published in Perspectives on Sexual and Reproductive Health, the study involved more than 800 women who sought abortions from 2008 to 2010 at 30 facilities.

The participants were surveyed one week after getting an abortion or being denied one. About 41 percent of women who had abortions said they felt regret, and 50 percent of those turned away felt regret. There was a much bigger difference in those feeling relief: 90 percent of women who got abortions felt relief, while 49 percent of those who were denied abortions felt relief. Those denied abortions also said they felt more anger and less happiness.

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