Maternal deaths caused by chronic hypertension continue to rise

‘Black women were at anywhere from three- to four-fold increased risk of dying ... compared to white women’

Chronic hypertension is contributing substantially to maternal deaths in the United States, with particular risk among Black women, according to new research from Rutgers Robert Wood Johnson Medical School’s Department of Obstetrics, Gynecology and Reproductive Sciences.

The study analyzed data from more than 155 million births and 3,287 hypertension-related maternal deaths among U.S. women ages 15-49 from 1979 to 2018. It found a 15-fold increase in maternal mortality rates associated with chronic hypertension over the 40-year period.

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“Overall hypertension-associated deaths declined in the U.S. over the last 40 years, but this decline is restricted to women who have pre-eclampsia/eclampsia as the cause,” said study author Cande V. Ananth, professor, vice chair for academic affairs, and chief of the Division of Epidemiology and Biostatistics in the Department of Obstetrics, Gynecology and Reproductive Sciences at Rutgers med school. “If you isolate the data on women who have chronic hypertension, which is defined as a pre-existing hypertensive condition or hypertension diagnosed within the first 20 weeks of pregnancy, as a cause, mortality rates have increased quite substantially — on average, by about 9.2 percent per year over the last 40 years. So it is the chronic hypertension that has really driven the maternal mortality trends in the U.S. over the last 40 years.”

Hypertension-related maternal deaths rose with age and were highest among women 45-49, and those with obesity, the study found.

The researchers also found a substantial race disparity in maternal mortality rates because of hypertension, Ananth said.

“Black women were at anywhere from three- to four-fold increased risk of dying from a hypertension-related cause compared to white women in the United States, and this disparity has persisted for the last 40 years,” he said in a Rutgers release, noting that problems with access to care and many risk factors for hypertensive complications are higher among Black women than white women, which contributes to this disparity.

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The study also offers insight for women and their health care providers, said Todd Rosen, associate professor and chief of maternal fetal medicine at Rutgers, who called the results concerning, though not necessarily surprising.

“Women are starting their families when they are older and they may be heavier and in a poorer state of health,” Rosen said. “For a portion of the time period studied, the CDC reported that the percentage of first births to women between 30 and 34 rose by 28 percent, and those for women 35 and older rose 23 percent. To help reduce hypertension-related deaths in these groups, we all need to work to ensure women are in optimal health before they start their families. The four-fold increased risk for mortality in Black compared with white women is especially concerning, and special attention needs to be focused to eliminate this disparity.”

The study was published in the December issue of Hypertension. For more content like this, sign up for the Pulse newsletter here.