Severe maternal morbidity — unexpected outcomes of labor and delivery such as heart attacks, obstructed labor, and hysterectomies — has been on the decline globally, but rates have steadily increased in the United States. According to recent data, the national rate has risen by 75% over the past decade, affecting more than 52,000 people giving birth annually in this country.
“[In] a lot of the European countries, we’ve actually seen declines in severe maternal morbidity since the ’80s, whereas in the U.S. it just keeps going up,” said Mary Regina Boland, an assistant professor of informatics at the University of Pennsylvania who studies the connections between human health and environmental exposures.
Doctors and clinicians don’t know why U.S. rates of severe maternal morbidity are increasing, Boland said, but she noted that they tend to study individual risk factors like obesity or heart disease to explore SMM’s prevalence in the population. The medical literature shows that Black and Asian women are more likely to develop SMM. Black women are at a 10-fold increased risk of experiencing one of the 21 SMM conditions compared with white women. But individual risk factors, like income and maternal education, alone have not explained this disparity.
Boland and her colleagues at Penn Medicine wanted to explore how individual and neighborhood-level stressors might account for the severe morbidity rate among people giving birth in Philadelphia. A recent study Boland co-authored, along with lead study organizer Jessica Meeker and a team of other researchers, analyzed 63,334 pregnancy deliveries during a seven-year period at four hospitals within the University of Pennsylvania Health System and compared health outcomes to U.S. Census data.
Their finding? Majority-Black neighborhoods had disproportionately higher rates of severe maternal morbidity. The rate of severe maternal morbidity within a neighborhood actually increased by 2.4% with every 10% increase in the percentage of individuals in a census tract who identified as Black or African American. Identifying as white was associated with lower odds of severe maternal morbidity at delivery.
The research team considered things like violent crime rates and number of housing units within a neighborhood that had quality issues, as well as the proportion of tenant-occupied homes versus owner-occupied homes. Boland said those characteristics are helpful for understanding maternal morbidity because they stand in for potential stressors people may be exposed to within a given neighborhood. Violent crime and racial composition of neighborhoods seemed to have the most impact on the severe maternal morbidity rates reflected in a given area, which Boland said is most likely due to some kinds of underlying environmental exposure the census data doesn’t capture.
One example of that, she said, is exposure to lead, which typically isn’t measured in Philadelphia on a neighborhood level.
“It’s usually collected among children in the public school,” said Boland. “But there can be disparities in terms of … how many houses have been tested. Lower-income homes often may be less likely to be tested, [and] also more likely to have overpaint.”
So it’s likely that there is more lead exposure in majority Black communities, and that could impact the maternal health of people giving birth who live in those neighborhoods. Boland said it’s clear that severe maternal morbidity disparities are not the product of biological or genetic dispositions, but rather are reflective of structural inequality on the neighborhood level. That’s why even white people who live in a racially segregated Black community are also more likely to develop such pregnancy-related complications as well.
“And so when we see … neighborhoods where more individuals identify as African American have a higher rate of severe maternal morbidity, the way we’re thinking about this is that these communities are historically disadvantaged communities and therefore the level of resources that they have [is related to] some aspect of housing or environment,” said Boland.
‘You might not be in poverty, but you might not have spare cash’
Research has shown how residential segregation has an impact on the health outcomes of communities still living in the wake of the intentional neighborhood restructuring of the past few decades. One significant iteration of that was redlining: In the United States, beginning in the early 1930s, the federal government intentionally segregated the country’s housing stock by refusing to insure mortgages in and near Black neighborhoods.
“At the same time, the [Federal Housing Administration] was subsidizing builders who were mass-producing entire subdivisions for whites — with the requirement that none of the homes be sold to African Americans,” web producers Bridget Bentz and Molly Seavy-Nesper wrote in 2017 for an episode of WHYY’s Fresh Air about the U.S. government’s role in segregating the country.
But Boland said past research that has tried to explore the connections between neighborhood-level factors like housing inequality and health outcomes has produced conflicting findings. Some studies show that segregation is associated with poorer birth outcomes for Black Americans. But there are also studies that demonstrate health benefits of living in predominantly Black neighborhoods.Boland says that has a lot to do with the distinct history and makeup of specific cities in America, she said. Many of these studies are conducted in places like New York City, where wealth inequality persists, but there is ample public transportation and significant city-level investment in job creation.
“So there’s certain things about New York City that are different … than, say, Philadelphia, where you don’t sometimes have the same accessibility across different neighborhoods in terms of bus systems and SEPTA,” said Boland.
A lot of health disparities research also comes out of California. And Boland says when you consider factors like housing in these studies, it’s important to note that Philadelphia is a substantially older city, with a lot of old housing that might contribute to a whole host of health issues that will not show up in California cities.
“You’re talking about homes from the 1800s,” said Boland. “How modernized they are may vary greatly, and there might be more lead poisoning in Philadelphia than … in California.”
Differences in how crime is reported also contribute to the conflicting research results that emerge from the larger question about how much neighborhood-level stressors have an impact on health and the body. Boland said one of the biggest surprises that emerged from her study was the lack of association she and her team were able to find between neighborhood-level poverty and severe maternal morbidity. But there’s a good reason why.
The poverty line is a national designation set by the federal government. According to Boland, federal standards for defining the poverty line are based on cities in the South and the Midwest, where poverty persists but the cost of living is substantially lower than cities in the Northeast like New York and Philly.
“In Philadelphia, you might be looking at one thousand dollar, two thousand dollar [rentals],” said Boland. “So when you have higher rent, you have to pay that every month … but you might still have trouble making your bills every month. You might not be in poverty [according to the federal definition], but you might not have spare cash.”
In other words, in Philadelphia you need more money to survive compared to other parts of the country. But because many struggling families are not classified as living under the poverty line under the federal standard, in some cases it reduces their chances to tap into federally funded programs that might provide resources like food, health insurance, housing — the basic necessities needed to live and be well. And Boland said those gaps in care can and often do turn into poor health outcomes down the line.
Clinicians don’t ask if your neighborhood is really stressful
The initial Penn Medicine study findings suggest that the role of neighborhoods in personal biology is real, and potentially plays a bigger role than some had imagined.
“A lot of times, clinicians kind of focus at the individual level, like, are you overweight or are you getting proper nutrition?” said Boland. “And sometimes less emphasis is placed on the communities in which you live.”
But she said this study presents a special opportunity to identify neighborhoods in Philadelphia where environmental and social stressors are disproportionately high, so community-specific interventions can take hold. Anything from improving access to nutritious foods, addressing air pollution, decreasing neighborhood violence, and increasing access to public transportation could help to address racial disparities in maternal health outcomes.
Community health workers, social workers, and neighborhood organizations have a role to play here too, Boland said. But so do health systems and clinical infrastructures. Your doctor can’t individually change how much lead you might be exposed to in your community, but Boland said they can start by asking the right questions.
“I think if we’re cognizant of the fact that they’re living in a stressful environment and that they might have these different stressors, we might be able to help a little bit more,” said Boland.
Screening questions for environmental and social stressors and more frequent checkups with patients are just some ideas. Maybe someone is afraid to leave home to pick up medication. If doctors assess that need from the beginning, Boland said, they could help set up delivery of medication for a patient.
“Clinicians don’t usually ask, like, you know, is the neighborhood in which you’re living very stressful,” said Boland. “High levels of chronic stress … wears on your body, and I think understanding that and thinking about that through the clinical pipeline will be important moving forward.”
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