The US maternal death rate has doubled. But why?

Read Advisory Board's take on this story.

More women die from pregnancy-related causes in the United States than in any every other developed nation—and the U.S. maternal mortality rate is increasing over time, Sarah Frostenson reports for Vox.

In most other wealthy countries, maternal death rates have dropped significantly since 1990. For instance, the rate in South Korea dropped from 20.7 deaths per 100,000 live births in 1990 to 12 deaths in 2013.

But according to CDC data, the rate of pregnancy-related deaths in the United States has more than doubled between 1987 and 2012—increasing from 7.2 to 15.9 deaths per 100,000 live births.

Higher than previously thought?

The maternal death rate in the United States may be even higher than previously reported, according to a study published last week in Obstetrics & Gynecology. Researchers from Boston University School of Public Health, the University of Maryland, and Stanford University Medical School adjusted previous National Center for Health Statistics and CDC data to account for differences in how states reported information on death certificates.

They found that the U.S. maternal death rate in 2007 was 68 percent higher than initially reported: 21.3 per 100,000 live births, rather than the officially reported 12.7. Based on the adjusted data, they found that the national maternal mortality rate increased from 18.8 per 100,000 live births in 2000 to 23.8 in 2014.

Regardless of the measurement approach, researchers agree that maternal deaths are increasing in the United States, and they offer several possible explanations.

Possible factors

Maternal fetal medicine by the numbers

Fewer women die today from complications directly related to pregnancy than in the 20th century. But CDC researchers told Vox that women are more likely to die because of preexisting chronic cardiovascular conditions, such as heart disease.  

William Callaghan, chief of maternal and infant health at CDC, explained that the patient population in the United States is growing more complex, which is contributing to more maternal deaths.

"We've seen a big bump in cardiovascular disease and chronic disease contributing to maternal deaths," he said. "Underlying heart disease is common, diabetes is common. We now have a group of women bringing with them into pregnancy their entire health history."

Thirty years ago, cardiovascular conditions accounted for less than 10 percent of all pregnancy-related deaths. Now, CDC says they comprise more than a quarter, making cardiovascular conditions the second-leading contributing factor to pregnancy-related deaths.

"It's a larger problem than just dealing with women during pregnancy, it's the health of our society," said Callaghan. "Imagine a [pregnant] woman comes in with [a body mass index] of 40, and she's 24 years old—that didn't happen in the past year, it happened in the past 24 years."

mHealth spotlight: High-risk prenatal care on your smartphone

Racial disparities

Research has found that black women in the United States are particularly likely to die from pregnancy-related causes. The disparity is increasing: Black women made up 34 percent of U.S. pregnancy-related deaths in 2007, but 42.8 percent of such deaths in 2011.

Black women are less likely to have early access to prenatal care and more likely to suffer from chronic conditions, but Vox writes that isn't enough to explain the disparity. A 2007 study found that black women are up to three times more likely to die in childbirth than white women, even after adjusting for age, education, and living conditions.

The US infant mortality rate is high—but not for the reason you might expect

Callaghan said, "It's the thing that wakes us up in the middle of the night as we try to understand it," adding, "It's access issues, differences in care based on geography, differences in health status—it's all these things … and we're not going to find the one thing that causes it."

Reduction efforts

Some research suggests as many as one-third of pregnancy-related deaths are avoidable. To reduce these deaths, CDC has partnered with the Association of Maternal & Child Health Programs to help states create boards that assess maternal deaths to find actionable trends.

In 2012, when the partnership began, 18 states had active maternal mortality review boards. This year, at least 38 states either have an active board or are in the process of creating one (Frostenson, Vox, 8/8; Norton, CBS News, 8/9; Cara, Medical Daily, 8/11; Boston University School of Public Health release, 8/10). 

Advisory Board's take

Tali Warburg, Service Line Strategy Advisor

The increase in high-risk pregnancies is a troubling trend, and one that directly contributes to increased maternal mortality. According to Advisory Board estimates, high-risk deliveries have a projected growth of 8 percent from 2015 to 2020, while low-risk deliveries have a projected growth of only 3 percecnt over the same time period. Obtaining prenatal care early is crucial and can prevent complicated and dangerous deliveries.

Hospitals are finding creative ways to provide prenatal care to women with high-risk pregnancies, such as building maternal fetal medicine telehealth programs. To learn about other creative ways that hospitals are transforming women's health, download our ready-to-present slides on women's health market trends. The slides provide an in-depth look at everything from growth outlooks and financial considerations to new care management priorities and technology innovations.

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