Barcelona awarded $2.1 million to examine racism, stress in pregnancy
In a research first, Columbia Nursing will study epigenomic changes associated with racism in Black pregnant women, to better understand the interplay among discrimination, the epigenome, and Black women’s worse health outcomes. Using data from one of the nation’s largest cohorts of pregnant women, principal investigator Veronica Barcelona, PhD, and her colleagues will analyze Black women’s DNA to see how individual and structural racism alter their gene expression. “We’re looking for a broader understanding of the forces affecting individual health throughout a woman’s lifetime and during pregnancy,” Barcelona explains. “We’re hypothesizing that these stressors get internalized and change expression of genes along stress pathways, leading to shorter gestation or preterm birth.”
Barcelona has received a $2.1 million R01 award—her first—from the Eunice Kennedy Shriver National Institute for Child Health and Human Development to fund a five-year study investigating these hypotheses, “Epigenomic Pathways from Racism to Preterm Birth.”
Preterm birth (gestation lasting less than 37 weeks) is a leading cause of perinatal morbidity and mortality in the United States. Black women are two to three times more likely than white women to experience preterm birth. They are also more likely to deliver low birthweight babies and to develop hypertensive disorders in pregnancy, such as chronic hypertension, preeclampsia, eclampsia, and gestational hypertension.
Although research has identified anti-Black racism as a root cause of such perinatal health inequities, the mechanism behind these effects remains unclear. Little is known, for example, about how Black women experience racism individually and structurally, and how these experiences interact to affect the molecular mechanisms leading to preterm birth.
Individual discrimination refers to racially driven assumptions about people and actions towards them. Structural racism refers to the multiple, mutually reinforcing ways societal institutions foster racism, which in turn reinforces biased beliefs, values, and resource distribution. In the new study, Barcelona and her team will look at six measures of structural racism: residential segregation, income, immigrant political climate, political participation, judicial treatment, and homeownership. They will conduct a secondary analysis of data from the Nulliparous Mothers to Be Study, which enrolled more than 7,000 Black and white women and was conducted from 2010-2015. Data include extracted maternal DNA from blood and information on pregnancy complications and birth outcomes. Barcelona’s new study will:
- Determine the interactive effects of individual- and structural-level racism on preterm birth among Black and white women
- Examine how racism changes expression of stress genes among Black women (n=1,306) to identify novel risk candidate genes for preterm birth
- Identify if epigenomic changes mediate the relationship between racism and preterm birth in Black women
Notably, Barcelona will examine how racism affects gene function among Black women and how that is involved in the pathway to preterm birth. “We’re looking at the epigenome of just Black women because they bear the brunt of ill health effects of racism in this country,” she explains. “We’re looking at how racism literally gets under the skin, how individual Black women internalize the stresses of racism that they experience in the world and around them, and how those stresses affect the epigenome, changing the expression of genes related to stress, and leading to babies being born too soon.”
Epigenomics is the study of reversible changes in methylation, a kind of “on-off” switch controlling gene expression. While these changes don’t alter a person’s DNA, patterns of methylation can be passed down to the next generation. Revealing how racism affects gene expression could help researchers understand the pathways that lead to adverse birth outcomes among Black women.
Many studies of epigenomics in pregnancy have under-represented Black women, and few have measured exposure to structural racism, notes Barcelona, a public health nurse and reproductive and perinatal epidemiologist. Those that have examined structural racism and PTB have not investigated its interaction with individual racism and their combined effect on birth outcomes, she said.
Moreover, few studies have examined epigenetic differences among Black women experiencing racism, and none have included pregnant women. “We’re proposing to look at racism individually and structurally to see if what we measure can provide explanations as to why there’s an excess of PTB in Black women,” Barcelona says. “We want to compare Black women who experience full-term pregnancy with those who experience PTB so we can bring down those numbers. This will be the largest study to examine multilevel racism factors and epigenomics in pregnancy among Black women.”
Multilevel racism refers to both individual and structural racism. “We hypothesize that Black women experiencing multilevel racism will have unique epigenetic signatures in stress gene pathways and higher odds of preterm birth than Black women with lower racism exposures,” Barcelona explains.
The study’s two main outcomes, she adds, will be to contribute epigenomic data towards discovery of mechanisms underlying preterm birth and other adverse birth outcomes in Black women, which could include gene therapies and pharmacologic interventions later on; and to inform local and state health policy development related to racism and perinatal health inequities across diverse geographic locations in the U.S. to reduce preterm birth.
“If we can learn more about what genes are affected in pregnancy then we can get on the very long road of developing a gene therapy or pharmacological interventions,” she adds. Ideally, the study could inform interventions at the individual, community, and policy level, including greater equity in political participation and home ownership, according to Barcelona. “This research is urgently needed to understand the root causes of PTB and to inform effective multilevel interventions to achieve health equity.”