The claim that women harm their health by choosing to terminate a pregnancy is baseless, according to a recent study. In fact, researchers found that those who undergo an abortion in the first or second trimester are less likely to suffer serious health complaints in the short term than those who are denied the procedure.

The results come from a fresh take on data collected as part of a 2014 survey on women's health. University of California researchers carried out their analysis on a longitudinal study of women who sought but didn't receive an abortion from early 2008 to late 2010.

It's called the Turnaway Study, and the survey's results have previously been used as evidence of the mental and physical consequences of being denied a desired termination.

Few debates are as emotionally and politically charged as the one on abortion rights, with facts often becoming muddied in a moral tug-of-war and misinformation spreading unchecked.

When it comes to using scientific evidence, pro-choice proponents have maintained the claim that the risks to a woman's wellbeing are serious enough that it should be up to her whether she should proceed with a pregnancy.

Meanwhile, opponents often cite studies identifying specific health risks such as future pregnancies developing placenta previa, or higher rates of mental health care among those who undergo an abortion compared with a generalised population.

Yet such arguments often hide the details of a more complicated story.

A 2018 University of Maryland study on the use of antidepressants among nearly 400,000 women found there was a difference in mental health between women who had an abortion and those who hadn't.

But on closer inspection, that difference already existed prior to the procedure, making more of a statement about the demographics seeking an abortion than any impact of the procedure itself.

Now, the landmark Turnaway Study provides researchers with a more accurate way to compare US women within the same population of people who face an unwanted pregnancy.

Researchers broke down roughly 900 of its self-reported responses into more than 700 who had first or second-trimester abortion, and around 160 who gave birth after being turned away from an abortion clinic.

Comparisons between the two groups on previous and ongoing health concerns revealed a number of significant differences.

Overall, women who had a first trimester abortion had a reduced chance of being in poor to fair health in the five years following the procedure. By comparison, women who gave birth showed an increased chance of expressing fair or poor general health.

Head pain also contrasted between the groups, with nearly a quarter of women who went on to give birth having migraines or headaches five years later, compared with just 18 percent for those who had an abortion.

Other chronic health problems also developed in higher numbers among the women who delivered a child, including asthma and joint pain.

Shockingly, a follow-up on survey volunteers revealed two participants who had sought abortions had subsequently died while pregnant, raising questions on whether such a tragedy might have been avoided had they received adequate healthcare.

The results put previous findings on the wellbeing of women seeking abortions into a new context, one that shifts the focus from broad comparisons and clinical diagnoses to a state of health from the point of view of the individual.

"We are listening to women's perspectives about their overall health status and not necessarily relying on new clinical diagnoses," obstetrician Lauren Ralph from University of California, San Francisco, told Time's Jamie Ducharme.

"This measure of self-rated health, I think, is actually more likely to encapsulate various aspects of their health and well-being that specific measures might not."

Others might disagree. The researchers admit it's hard to tell if the adverse health responses were all due to childbirth, or the stress of raising a newborn. There was also no difference in health insurance coverage in ensuing years, providing a point of contrast with the findings.

The role of science in the ongoing debate over abortion is tenuous at best. Philosophical divisions over the definition of human life and the value of body autonomy can't be solved with statistics and biology.

But where science is referenced, the context of hard data matters.

"The argument that abortion harms women is certainly not supported by our data," says Ralph.

This research was published in the Annals of Internal Medicine.