Laurie Bertram Roberts was 17 years old and 12 weeks pregnant when she noticed a pink discharge running down her leg one day. When she went to her local hospital in Michigan City, Indiana, doctors told her she may be having a miscarriage, and to go home and come back if she started to bleed.

The next day, bleeding heavily, Bertram Roberts returned to the ER, only to be sent home again because her doctors could detect a faint fetal heartbeat.

“It was kind of like, go home, you’re having a miscarriage, good luck,” said Bertram Roberts.

Later that evening, as the bleeding intensified, Bertram Roberts decided against going back to the hospital. She figured it would pass, and besides, she didn’t have the money to afford another ER visit. She visited her grandmother, who lived next door, in order to make an unrelated phone call to her mom.

“I don’t remember what my mom said, I just remember hitting the floor,” she said. In the moments that followed, Bertram Roberts said she could hear her then-husband and grandmother calling her name as if through a tunnel, but she couldn’t open her eyes. “I remember feeling like I was dying.”

It wasn’t until after her eventual recovery that Bertram Roberts found out why she had been turned away at the ER on her second visit. Because it was Catholic, the hospital followed ethics and religious directives set out by the U.S. Conference of Catholic Bishops, which prohibit pregnancy terminations, tubal ligations, fertility treatments, and birth control pills. Because the doctors were able to detect a faint heartbeat, doctors treated her miscarriage like an abortion, according to Bertram Roberts.

In the United States, Catholic ethics directives apply to one in six hospital beds, and the prohibited procedures most often involve reproductive health, meaning they disproportionately impact women. And as The New Republic reported in 2016, Catholic ethics restrictions have even spread to secular hospitals through opaque sales and merger contracts that leave patients in the dark about what care is or isn’t available.

According to new research published today by the Columbia Law School Public Rights/Private Conscience Project and Public Health Solutions, women of color like Bertram Roberts are even more likely to be treated at Catholic hospitals where religious doctrines dictate medical practices.

The report includes some startling data. For example, in New Jersey, women of color make up half of all women of reproductive age but 80 percent of births at Catholic hospitals. And in Maryland, black women had almost 3,000 more births at Catholic hospitals than white women, despite the fact that they had over 10,000 fewer births overall. In 19 of 33 states and one territory, Catholic hospitals reported a higher percentage of births to women of color than did non-Catholic hospitals.

“The findings outlined in this report indicate that women of color are at greater risk of being denied care due to religious restrictions when they need it most—during childbirth,” said Elizabeth Reiner Platt, director of the Public Rights/Private Conscience Project and co-author of the report.

The extent to which Catholic hospitals are able to act on their ethics directives varies from state to state, where religious refusal laws provide more or less leeway for providers to deny coverage on religious grounds. The laws differ in terms of what procedures they cover, which medical providers are exempted (individual doctors versus the entire hospital), and what the exemptions entail (protection from civil vs. criminal liability).

Heath care providers in New Jersey are currently shielded from civil and criminal liability for refusing to “perform, assist in the performance of, or provide abortion services or sterilization.” In Maryland, hospitals cannot be required to refer patients to providers of artificial insemination, sterilization, or termination of pregnancy. Religious exemptions exist on a federal level too. On Thursday, the Department of Health and Human Services announced the creation of a “conscience and religious freedom division” which is expected to protect health care workers seeking to opt out of procedures like abortion or treating transgender patients.

It’s not news that women of color—and black women in particular—face greater barriers to health care across a wide range of services. This so-called health care gap stems from a number of factors, including economic inequality and structural discrimination, which often work in tandem. Last year, researchers found that black women are approximately twice as likely to die of cervical cancer, and an analysis by ProPublica showed how women who deliver at hospitals predominantly serving black women are at higher risk of harm. The impact of Catholic ethics restrictions on women of color should be examined alongside these trends.

“What the Columbia report highlights is ways in which religious health care can pose an additional barrier to women in communities that are already impacted by these inequalities,” said Dr. Debra Stulberg, a University of Chicago professor whose research explores racial and socioeconomic disparities in reproductive health in the United States.

Platt stressed that the PR/PC report is not intended to make any correlation between maternal mortality and the rates of Catholic hospital usage. Rather, she said, the report highlights additional vulnerabilities women of color face when it comes to reproductive care. The report also doesn’t examine why it is that women of color are more likely to be treated in Catholic hospitals, something Platt hopes future research will address. But there is evidence that the racial disparities are linked to economic factors.

For Bertram Roberts, who is 39 and now lives in Mississippi, the nearby Catholic hospital was the only viable option she had when she lived in Indiana.

“When I got pregnant a few months later, it was the same hospital I had to go to for free maternity health care when I was waiting for my Medicaid,” she said. “The catch-22 for black women a lot of times, especially low income black women, is that the Catholic hospitals also tend to have the free programs.”

Bertram Roberts is now a reproductive rights activist, full-spectrum doula, and executive director of the Mississippi Reproductive Freedom Fund, so she has learned to navigate the arcane religious guidelines that pervade U.S. hospital systems. But at the time of her miscarriage, Bertram Roberts said she was never told that a neighboring hospital would have helped her end her pregnancy. Even if she had had the financial resources to go elsewhere, she wouldn’t have known to do so.

“It’s not like they’re being up front about it,” she said. “As a patient, I should be able to know that. But more than that, this shouldn’t even be an issue. Because it’s not like we have equal access to go somewhere else. So you’re literally putting people’s health at risk because of your religious doctrine.”

Catholic hospital systems have often defended themselves against criticism of their ethics directives by arguing they are often the only ones providing any health care in underserved and marginalized communities. As it turns out, Catholic hospitals actually provide less charity care than public hospitals and other religious non-profit hospitals, according to a 2013 report by the American Civil Liberties Union and MergerWatch, a non-profit that tracks hospital mergers.

“We’re supposed to be grateful,” said Lori Freedman, a medical sociologist at the University of California. “But if these are areas where people already have unequal access to care, and the only people who provide care will only provide partial care, it just seems to compound the unfairness.”

In order to address these disparities, the authors of the Columbia report outline several policy proposals, including regulations that hospitals notify patients up-front about their religious restrictions, and legislation to limit religious carve-outs for health care providers.

“It really should not be a difficult lift to get state legislatures to amend religious refusal laws to make it clear you can’t deny someone emergency medical services,” said Platt. “That said, we’re in a world in which state legislators are competing in a race to the bottom to be the most restrictive on reproductive health care.”

Indeed, there’s a big difference between allowing individual doctors and nurses to opt out of procedures and allowing massive hospital systems to effectively shut off access to necessary reproductive health care.

“My grandmother used to always say, if you want good health care, go to the Catholics,” said Bertram Roberts, who grew up in an evangelical Christian household. “It’s the best care until it’s not, until they tie the hands of their providers.”