With anti-abortion legislation sweeping the country in recent months, insurance coverage for the procedure has emerged as a battleground.

A number of Democratic presidential candidates have called for the repeal of the Hyde Amendment, which bars federal Medicaid funds from covering most abortions. Meanwhile, abortion opponents continue to speak out in favor of keeping Hyde and states like Ohio are moving to also restrict private insurance coverage of the procedure.

But amid this debate, there’s been a lack of up-to-date research on what actually happens to pregnant people when they want an abortion but their insurance won’t cover it. To answer that question, researchers at Advancing New Standards in Reproductive Health (ANSIRH), a group at the University of California San Francisco, surveyed pregnant women in Louisiana on whether they had ever considered abortion. For those who considered the procedure but didn’t have one, researchers asked if lack of Medicaid coverage was part of the reason why. The research, published on Wednesday in the journal BMC Women’s Health, was provided to Vox exclusively ahead of publication.

Based on the women’s responses, the researchers estimated that about 29 percent of Louisiana women who would have had an abortion if Medicaid covered the procedure instead chose to give birth. “Lack of Medicaid funding for abortion remains an insurmountable barrier to abortion care for a substantial portion of low-income women,” Sarah Roberts, an associate professor at ANSIRH and one of the authors of the study, told Vox.

Abortion opponents see preventing the procedure as a positive thing: “The Hyde Amendment has saved the lives of more than 2 million Americans who otherwise would have been victims of taxpayer-funded abortions,” said Marjorie Dannenfelser, president of the Susan B. Anthony List, in a statement earlier this month. But previous research shows that people who seek abortions but can’t get them are at risk for a number of ill effects, from financial insecurity to difficulties bonding with their children, Roberts said.

Overall, the new research is a reminder that Hyde’s effects are real and significant. Near-total abortion bans at the state level have brought the possibility of a challenge to Roe v. Wade to the forefront of public conversation. But the ANSIRH study is yet more evidence that for many Americans, especially those in poverty, the end of Roe is already here.

The study shows that Hyde acts as an abortion ban for some people

First passed in 1976, the Hyde Amendment bans the use of federal funding for abortions except in the case of rape, incest, or a threat to the life of the pregnant person. That means Medicaid, the federal health care program serving low-income Americans, can’t cover most abortions. Some state Medicaid programs offer coverage using state dollars — Maine, for instance, recently passed a bill allowing its state Medicaid insurance, MaineCare, to cover abortions. Others, however, ban the use of state funds as well as federal funds to pay for abortions.

When insurance doesn’t cover abortion, the cost can be prohibitive. In a 2014 study, also by Roberts and her team, the median out-of-pocket cost for an abortion without insurance was $575. For over half of the women in the study, that amounted to more than a third of their personal monthly income.

For some pregnant people, research shows that “having to come up with the money leads to delays in paying bills or challenges paying rent,” or in delays in being able to get the procedure, Roberts said. For others, her team found, it leads to not getting the procedure at all.

For the study published on Wednesday, part of a larger project investigating the effects of abortion restrictions, Roberts and her team surveyed about 270 pregnant Louisiana women, most of whom were of low socioeconomic status. They chose Louisiana because it has many restrictions on abortion, including a ban on using state Medicaid funds for the procedure.

The researchers asked the women a variety of questions about their pregnancies, including whether they had wanted an abortion when they first found out they were pregnant, whether they had taken steps to get an abortion, and, if they had initially wanted an abortion but not received one, what had influenced that decision. They also asked the women what kind of insurance they had.

Based on their data, the researchers estimated that about 29 percent of Medicaid-eligible women across Louisiana who would get abortions if Medicaid covered them choose to give birth instead. They also estimated that lack of Medicaid coverage leads 3,000 women to give birth every year who would otherwise choose abortion. That’s in line with previous research on Medicaid coverage and abortion, based on data from the 1980s and ’90s, Roberts said.

Abortion opponents have backed the Hyde Amendment in part because it leads to fewer people getting abortions. A 2016 report published by the anti-abortion Charlotte Lozier Institute states that “over 20 studies in a variety of peer-reviewed academic journals demonstrate the Hyde Amendment and other laws to limit public funding of abortion reduce abortion rates and protect unborn children.”

But according to Roberts, research shows that people who want abortions but can’t get them face a variety of risks compared to people who are able to get the procedure. “Being unable to obtain a wanted abortion leads people to be tethered to violent men,” she said. “People who are denied an abortion are more financially insecure over time than people who are able to obtain an abortion” and face both short- and long-term risks to their health.

Research also shows that children of people who want abortions but are unable to get them are less likely than other children to meet developmental milestones and more likely to experience challenges in bonding with their mothers, Roberts said.

Abortion rights groups have been pushing for a repeal of Hyde for years, arguing that it essentially creates a two-tiered system in America where middle-class and wealthy people can get abortions but many low-income people cannot. The ANSIRH study, advocates say, bears out their concerns.

“ANSIRH’s study findings show we must repeal discriminatory abortion policies and demand abortion be fully covered by all health insurance, both public and private, to ensure everyone is free to decide if, when, and how to grow their families free from economic coercion,” said Yamani Hernandez, executive director of the National Network of Abortion Funds, in a statement.

The study also reveals some of the reality of abortion in America today. The procedure remains legal in all 50 states — none of the recent bans has actually gone into effect. But legal doesn’t mean accessible, and for about a quarter of low-income women, the Hyde Amendment is acting as a de facto abortion ban.

As 2020 candidates discuss the issue on the campaign trail, they’ll need to reckon with that fact.