For several months, ProPublica has been publishing an excellent and important series of stories — Lost Mothers: Maternal Care and Preventable Deaths — on the shameful patterns of maternal mortality in the US. Last month, articles focused on a particularly disturbing element: the shockingly high rates of maternal deaths in black women when compared to women of other races and ethnicities.

In an article co-published by ProPublica and NPR, Nina Martin and Renee Montagne summarize the disparities:

According to the CDC, black mothers in the U.S. die at three to four times the rate of white mothers, one of the widest of all racial disparities in women’s health. Put another way, a black woman is 22 percent more likely to die from heart disease than a white woman, 71 percent more likely to perish from cervical cancer, but 243 percent more likely to die from pregnancy- or childbirth-related causes. In a national study of five medical complications that are common causes of maternal death and injury, black women were two to three times more likely to die than white women who had the same condition.

Higher rates of poverty and lower average educational attainment aren’t entirely to blame, either. As Martin and Montagne illustrate with the story of 36-year-old Shalon Irving, black women with higher socioeconomic status face greater risks than less-advantaged white women. Irving earned a double PhD in sociology and gerontology, and was a lieutenant commander in the U.S. Public Health Service Commissioned Corps and a CDC epidemiologist researching how structural inequality, trauma, and violence influence health. Yet she died from complications of high blood pressure three weeks after giving birth to her daughter, Soleil.

Martin and Montagne consider some of the factors that make giving birth so much riskier for black women. One is that living in a society where racism and structural inequities are rampant represents a source of chronic stress; University of Michigan School of Public Health professor Arline Geronimus describes the effect of such stress as “weathering,” and found evidence of greater cellular-level aging in black women than white women.

For their examination of racial disparities, ProPublica analyzed two years of hospital inpatient discharge data from New York, Illinois, and Florida to examine how hospitals treat women who experience hemorrhages while giving birth — a common cause of maternal death that varies little by race. They identified 67,000 cases of maternal hemorrhage in these three states in 2014 and 2015. Based on research findings that hospitals where a larger share of mothers are black have more patients with severe delivery-related complications, ProPublica categorized hospitals as low, medium, or high black-serving. Annie Waldman reports:

While a handful of low black-serving hospitals had high complication rates, our analysis found that, on average, outcomes at hospitals that served a high number of black patients were far worse.

In New York, on average, high black-serving hospitals had complication rates 21 percent higher than low black-serving hospitals. In Illinois and Florida, high black-serving hospitals had complication rates 11 percent higher.

When we limited our patient pool to only mothers of average birthing age — between 25 and 32 — who did not have any chronic conditions like heart disease or diabetes, the pattern remained largely the same. This bolstered the notion that differences in care, along with patient characteristics, affected outcomes.

Deeper analysis of the data for each state underlined this finding. At low black-serving hospitals in New York, just under a third of the women who hemorrhaged had complications. At high black-serving hospitals, that rate climbed to about half.

Waldman illustrates the toll of fatal hemorrhage complications with the story of 33-year-old Dacheca Fleurimond, a Brooklyn home health aide who died just after giving birth for the sixth time at SUNY Downstate Medical Center, to twins Kayden and Jayden. Waldman reports that while this hospital has a “best practices” protocol for maternal hemorrhage, it does not explicitly include some steps recommended by the California Maternal Quality Care Collaborative, such as “keeping carts stocked with supplies to stave off massive bleeding and holding drills to simulate severe hemorrhage events.” Dr. Ovadia Abulafia, the chair of SUNY Downstate’s department of obstetrics and gynecology, notes that the hospital serves a particularly high-risk population. Here’s what another obstetrician-researcher told Waldman:

But Dr. Allison Bryant Mantha, a high-risk obstetrician and health care disparities researcher at Massachusetts General Hospital, said hospitals shouldn’t use demographics or patient characteristics to excuse poor outcomes. Instead, they should hone their practices to deliver the care their patients need.

“Hospitals have to own the conditions that women walk in with,” Bryant said. “You have to give patients what they need to get to a quality level of care. We are doing a good job of equal care, but not adjusting for needs.”

The two articles explore several likely factors in maternal mortality disparities, including the chronic stress of racism; structural factors like insufficient models for postpartum care and inadequate parental leave and childcare; hospital practices that don’t adequately address black mothers’ needs; and harmful racial stereotypes that can result in individual black women not getting the best care prenatally or when they present with postpartum complications. Both articles — Martin and Montagne’s “Nothing Protects Black Women From Dying in Pregnancy and Childbirth” and Waldman’s “How Hospitals Are Failing Black Mothers” — are well worth reading in full. Adriana Gallardo’s “Black Women Disproportionately Suffer Complications of Pregnancy and Childbirth. Let’s Talk About It.” also helps convey the kinds of complications and challenges black mothers encounter, and includes audio files that let us hear women telling their own stories.

The ProPublica series is doing important work to draw public attention to the problem of maternal mortality in general and racial disparities in particular, as well as to the important work researchers, public officials, and advocates have been doing to improve outcomes. After establishing the California Maternal Quality Care Collaborative a decade ago, California has reduced its maternal mortality rate at a time when the country’s rate has risen. The American College of Obstetricians and Gynecologists has formally adopted recommendations to reduce racial and ethnic disparities in health and healthcare. The SisterSong Reproductive Justice collective and Center for Reproductive Rights co-founded the Black Mamas Matter Alliance to cultivate research, change policy, advance care for black mothers, and shift the culture on black maternal health, while centering the voices of black mothers. All of this much-needed work to reduce the appalling racial disparities in US maternal mortality will be an uphill struggle, though, as long as this country’s racism, structural inequities, and hostility to women’s reproductive rights persists. We’ve got a lot of work to do.