Chronic hypertension has become a major cause of death during and after pregnancy, despite a 40-year decline in overall deaths tied to hypertension among pregnant people, according to new research from Rutgers Robert Wood Johnson Medical School.

The four-decade decline in hypertension deaths is driven by a precipitous drop in deaths related to preeclampsia, when someone who did not previously have high blood pressure develops the condition in the 20th week of pregnancy or later. Public health campaigns and updated medical guidelines have dramatically improved screening for preeclampsia and early intervention to manage the condition.

But findings from the Rutgers study, published in the December issue of Hypertension, suggest that chronic hypertension remains a major problem during pregnancy, especially for Black women.

“We have gotten much better at treating women with preeclampsia/eclampsia during pregnancy, which has undoubtedly contributed to the decline in maternal death rates, but we haven’t done as good a job in treating women with chronic hypertension,” said Cande V. Ananth, chief of the Division of Epidemiology and Biostatistics in the Department of Obstetrics, Gynecology and Reproductive Sciences at Rutgers Robert Wood Johnson Medical School and the study’s lead author.

Deaths from chronic hypertension, which is blood pressure of at least 130/80 mmHg, rose an average 9.2% a year between 1979 and 2018 according to the study, which analyzed data from more than 155 million births among women aged 15 to 49 during the 40-year period. Black individuals were up to four times as likely to die from chronic hypertension during pregnancy compared with white people.

The U.S. Centers for Disease Control and Prevention estimates that half of adults have high blood pressure or are taking medication for it, and the condition is a primary or contributing factor in about half a million deaths annually. Only a quarter of people with hypertension are properly managing it, according to the CDC. The condition is more prevalent among Black Americans compared with white Americans.

While a concern for anyone, high blood pressure can be particularly troubling during pregnancy. Decreased blood flow to the placenta could lead to low birth weight, premature birth, and other developmental problems for the baby, and organ damage for the pregnant person.

Some but not all blood pressure medications are safe to take during pregnancy, but many women may not know they have high blood pressure until they being routine obstetrics visits, where their vital signs are recorded every time.

Weight, diet and lifestyle — as well as heredity — are all factors that can contribute to high blood pressure, but don’t explain the racial gap in hypertension deaths among pregnant people.

“Most commonly what we see is, we blame the patient — she came into the pregnancy unhealthy,” said Nastassia Davis, a nurse researcher at Montclair State University in New Jersey.

The gap is another example of how structural racism has deeply affected people’s health and longevity, Davis said. She is also founder of the Perinatal Health Equity Initiative in East Orange, N.J., which provides new mothers with breastfeeding and postpartum support, and advocates for Black women’s health issues.

Overall, Black people are two to three times as likely to die during pregnancy or childbirth compared with white people, and that likelihood increases with age according to the CDC. The disparity exists even when researchers compare people of similar health status, income level and education.

In Philadelphia, 73% of pregnancy-related deaths between 2013 and 2018 were among Black people, even though they accounted for just 43% of births.

Much of the problem, Davis said, is that medical professionals do not listen to Black patients and treat them differently from white patients — even if unintentionally.

“A lot of it has to do with not being listened to, with trust not being established,” she said. “Do you even bother speaking up, if no one is listening?”

Research has shown that Black patients experienced better outcomes when treated by Black doctors. Other studies have shown that patients feel a stronger connection and greater trust with doctors who look like them.

“They’re being cared about as a person, not just cared for as a patient,” Davis said.

The COVID-19 pandemic has drawn attention to the myriad ways racism has affected people’s health, and Davis is hopeful that the public’s interest and sense of urgency in addressing these long-standing problems will outlive the pandemic.