News regarding the maternal mortality rate in the U.S. over the past several years has been bleak: It’s higher than it should be, in comparison to other countries; there are glaring racial disparities; and this is the only developed country where the number of deaths is rising.
But new data calls that last finding into question, suggesting that a change in the way maternal deaths were tracked is responsible for the uptick.
What counts as a maternal death?
Tracking maternal deaths sounds like it should be a straightforward matter. After all, either a person is pregnant or they are not. But establishing the cause of someone’s death, and determining whether or not pregnancy played a role, can be tricky.
“Maternal mortality is an extremely challenging figure to estimate,” Dr. K.S. Joseph, author of a new study about maternal mortality in the U.S., and a professor at the School of Population and Public Health at the University of British Columbia, told HuffPost.
A maternal death is defined as one that occurs while a person is pregnant or within 42 days of the termination of the pregnancy, whether the pregnancy ends in birth, miscarriage or abortion. (Note that this differs from a “pregnancy-related death,” which, by some definitions, can occur up to one year following birth.)
The maternal mortality rate is reported as the number of deaths per 100,000 live births, and it is often used as a sign of the general health of a population or the strength of a country’s health care system.
Joseph said the challenge of accurately estimating maternal mortality “is evident from how three agencies in the United States come up with three different numbers.”
He is referring to the National Vital Statistics System (NVSS), which is part of the Centers for Disease Control; the Pregnancy Mortality Surveillance System, another branch of the CDC; and the maternal mortality review committees in each state. They do not all tabulate maternal deaths in exactly the same way, or reach the same conclusions.
In an effort to improve the tracking of maternal deaths, which, in addition to these discrepancies, are often believed to go undercounted, the National Center for Health Statistics in 2003 recommended the addition of a “pregnancy checkbox” on death certificates to indicate whether the deceased was pregnant, or had been pregnant in the past 42 days or year.
States adopted the checkbox, but it was hard to ascertain the impact because they did not all adopt it at the same time but rather individually over a number of years. Counts of maternal deaths went up — as it was thought they would, since they were believed to have been undercounted previously. But there were also clear signs of inaccuracies. The pregnancy box was checked, for example, on the death certificates of 147 women ages 85 and over in 2013, Joseph explained.
To prevent this specific error, age limits were later used, but questions remained about the accuracy of the checkbox method.
An alternate explanation for a rising maternal mortality rate.
According to data from the U.S. National Vital Statistics System, there were 754 maternal deaths in 2019, 861 in 2020 and 1,205 in 2021. That’s an increase from 20.1 deaths per 100,000 live births in 2019 to 32.9 deaths per 100,000 live births in 2021 — an alarming rise widely reported in the media and used to advocate for changes to the current system of maternity care.
But does this rise indicate an increase in the number of people dying, or is it a consequence of the pregnancy checkbox?
To answer this question, Joseph and his colleagues, in their study published in the American Journal of Obstetrics and Gynecology, undertook a recount of all maternal and pregnancy-related deaths in the U.S. between 1999 and 2021. Using NCHS data, they counted these deaths in two ways.
First, they used the same methods as the NVSS, relying on the checkbox, and found the same increase in the number of deaths. Second, they used an alternate method, in which deaths were only counted as maternal ones if a pregnancy-related cause of death was listed.
“Up to 20 causes of death can be listed by the certifying physician. And if any one of them mentioned pregnancy as a cause of death, we counted that as a maternal death,” Joseph explained. However, if the pregnancy box was checked but no pregnancy-related cause of death was listed, the researchers did not count it as a maternal death.
When tabulated this way, the researchers found that the maternal mortality rate in the U.S. did not go up. It remained relatively stable, in fact.
Using the NVSS method, the average maternal mortality rate from 2018-2021 was 23.6 deaths per 100,000 live births, but using the researchers’ alternate method, it was only 10.4 deaths per 100,000 live births.
Because of the way the data was recorded, researchers were unable to determine why the pregnancy checkbox was marked so many times in error. They conclude, “Maternal death data from 2003 to 2017 cannot be taken at face value.”
Racial disparities persist.
While this is reassuring news for many people in the U.S. who are either pregnant or planning a pregnancy, it is important to note that the racial disparities found in the NVSS data did not disappear when calculated using the alternate method.
According to NVSS data, non-Hispanic Black people were 2.6 times as likely to die as a result of pregnancy than non-Hispanic white women and people in the years 2018-2021. Using their alternate method, Joseph and his co-authors found a similar ratio over those same years. They calculated that non-Hispanic Blacks were 2.9 times as likely to die as non-Hispanic whites from all causes of maternal deaths.
This new interpretation of the data does not find an overall increase in maternal mortality, and it situates the U.S. in a better position relative to other developed countries when it comes to our maternal mortality rate (on par with Canada’s, Joseph said, with the caveat that countries do not all use the same criteria to track maternal deaths and so the data are of limited use). But the racial disparity is glaring.
“We need to do better with regards to caring for people of color, and in combating structural racism and access to care issues and prejudice,” Dr. Justin Brandt, a co-author of the study and a maternal-fetal medicine specialist at NYU Langone, told HuffPost.
“Until we can make serious changes in that area, disparities are going to persist,” he said.
Why accurate data matters.
Having accurate data, Brandt said, is an important preliminary step in tackling these disparities. If we don’t know which health problems are leading to maternal deaths, we won’t be able to focus with precision on their prevention.
For example, their study (and others) identify hypertension and cardiovascular disease as a driver of maternal death that disproportionately impacts Black people. It’s critical for providers, and those who make structural decisions about health care, to have this information.
“Once we have the most accurate picture of health care in the United States, and specifically maternal mortality trends in the United States, then we can target our approach more effectively,” Brandt explained.
While the number of deaths may be smaller than previously thought, both Joseph and Brandt emphasized that even one maternal death is too many. Brandt said that he hopes this research, rather than diverting funding and attention from the problem, can help focus resources on the specific causes of these deaths.
“This data, I think, is critically important in helping us to hopefully someday make this so that there are no deaths,” Brandt said.
With this new and more accurate data, Joseph said, “We can zero in on what are the specific causes of death among the non-Hispanic Black population that is leading to this disparity,” such as hypertension and cardiovascular disease.
“This gives us some direction or a target that we can focus on in terms of mortality initiatives to improve preconception and pregnancy help for non-Hispanic black women,” he continued.
Dr. Auja McDougale, an OB-GYN at New York-Presbyterian in Manhattan not affiliated with the study, believes “the reason why it’s important for us to standardize how we collect that data is so that we can look at the data not only as it relates to specific populations, but how we can now have specific programming and strategies to mitigate the risk for those high risk populations.”
McDougale told HuffPost that in working with a “very diverse” patient population, she wants her patients “to understand that we partner in the decisions of your pregnancy and we have a number of things that we can do to make sure that you and your baby are healthy. So although the statistics and the rates, they can be scary, it doesn’t necessarily tell the whole story based on your own personal needs.”
McDougale said she works with each patient towards the goal of a healthy baby and the healthiest pregnancy possible.
Brandt explained that he talks with patients “about the reality of our medical system and why it’s important that they advocate for their needs.”
“I tell my patients that if they ever feel that the clinicians are not listening, to say, ‘I don’t think you’re hearing me’ or ‘I’m not being heard.’ So I think patients understand that they’re a partner in the process.”