In 2007, a team of researchers designed an experiment.
They visited 30 abortion clinics over three years, and recruited more than 1000 women in waiting rooms.
A quarter of those women were denied an abortion, having missed the prescribed time limit set by the clinic. Some missed it by only a matter of days.
The entire group - from different backgrounds, circumstances and age groups - were interviewed twice a year for five years.
The result was a remarkable piece of research dubbed the Turnaway Study that took 10 years to both collect and deconstruct.
For the first time ever, demographers were able to enrich public debate on abortion with real-life data, science and comparison, and give us tangible insight into an age old question: What are the consequences of having, or being denied, an abortion?
In this article, we explore what they discovered.
The journey from seeing those double lines, to deciding now isn't the time to become a mother, is an experience fraught with emotion. But as this study concludes, it's not a decision that often leads to regret.
For many women, access to abortion has given them the opportunity to live a life they otherwise may not have had. But for some, the right to make that decision is taken away by the rules and regulations of the country or state in which they live.
WATCH: The women forced to have illegal abortions. Post continues after video.
The women in the Turnaway Study came from 21 American states. Of those denied an abortion, 70 per cent carried the unwanted pregnancies to term. Others miscarried or were able to obtain late abortions elsewhere - and the research shows that on average, the women in this group lived below the poverty line.
As the New Yorker explains, travel expenses to get to an abortion clinic, and raising the money to pay for a procedure, are just two of the reasons a woman might not be able to get to a clinic in time - with some women in the study turned away a day or two after missing the 'cut off.'
As Department of Obstetrics, Gynecology & Reproductive Sciences Professor Diana Greene Foster, PhD, writes in her newly released book The Turnaway Study: Ten Years, a Thousand Women, and the Consequences of Having—or Being Denied—an Abortion, the two groups of women were "remarkably similar at the first interview".