Portra Images via Getty Images

Anti-abortion legislators around the country have been passing restrictions in the name of women’s health for years.

But a major longitudinal study shows that women who are denied abortions — and go on to have a baby — have worse health outcomes years later than women who receive an abortion.

The latest findings from the Turnaway Study, conducted by researchers at the University of California, San Francisco, compared the health of roughly 330 women who had an abortion during their first trimester with 380 who had an abortion during their second trimester and just over 160 who tried to get an abortion but who were turned away. The latter women were denied access to the procedure because they were over their clinic’s gestational limits.

Five years after the women either had an abortion or were denied one, they answered questions about their overall health, as well as specific concerns like chronic pain, headaches and hypertension.

The women who were able to get an abortion generally rated their health about the same whether the procedure took place during the first or second trimester.

But the women who were denied an abortion and went on to have a baby fared worse.

Some 27% said their health was “fair” or “poor,” compared to 20% of women who had a first-trimester abortion and 21% who had a second-trimester abortion.

They also reported more headaches and joint pain, although all three groups had similar rates of other types of chronic pain and obesity.

“The argument that abortion is harmful to women’s health is certainly not supported by the data,” Dr. Lauren Ralph, author of the study and an epidemiologist with the university’s Advancing New Standards In Reproductive Health project, told HuffPost.

“Instead, we consistently found that when differences did emerge, women who were denied abortions and gave birth fared worse,” she said.

The new findings do not establish cause and effect, so it is unclear exactly why women who were denied an abortion reported worse health outcomes years later. Ralph said that in some cases, childbirth could have exacerbated existing health problems the women already had. Pregnancy and childbirth can also cause long-term health issues such as joint pain.

But that is likely not the full picture.

“There is this complex relationship between health, socioeconomic status and stress,” Ralph said. “I would guess there are a number of factors.”

The vast majority of American states prohibit abortion after a certain point in pregnancy. Roughly half have laws setting that ban as early as 13 to 24 weeks — roughly the second trimester ― often based on the unscientific claim that a fetus can feel pain around 22 weeks.

And some states have begun restricting abortion at much earlier stages of pregnancy, like the recent surge in bans on abortion at six or eight weeks gestation. None of those laws are currently in effect, and many are facing legal challenges.

The Turnaway Study tracked nearly 1,000 women overall, recruited at 30 abortion clinics across 21 states, between 2008 and 2015. The study team spoke with them on the phone one week after they either had or were denied an abortion, and then semi-annually for five years.

Previously, researchers using that same dataset found that women who got an abortion had no long-term adverse mental health effects. Women who were turned away, however, reported greater anxiety and lower life satisfaction and self-esteem soon after they were told they couldn’t have an abortion.

Medical organizations like the American College of Obstetricians and Gynecologists emphasize that access to abortion is an integral part of women’s health care.