Trends in State-Level Maternal Mortality by Racial and Ethnic Group in the United States

Abstract

Importance: Evidence suggests that maternal mortality has been increasing in the US. Comprehensive estimates do not exist. Long-term trends in maternal mortality ratios (MMRs) for all states by racial and ethnic groups were estimated.

Objective: To quantify trends in MMRs (maternal deaths per 100 000 live births) by state for 5 mutually exclusive racial and ethnic groups using a bayesian extension of the generalized linear model network.

Design, setting, and participants: Observational study using vital registration and census data from 1999 to 2019 in the US. Pregnant or recently pregnant individuals aged 10 to 54 years were included.

Main outcomes and measures: MMRs.

Results: In 2019, MMRs in most states were higher among American Indian and Alaska Native and Black populations than among Asian, Native Hawaiian, or Other Pacific Islander; Hispanic; and White populations. Between 1999 and 2019, observed median state MMRs increased from 14.0 (IQR, 5.7-23.9) to 49.2 (IQR, 14.4-88.0) among the American Indian and Alaska Native population, 26.7 (IQR, 18.3-32.9) to 55.4 (IQR, 31.6-74.5) among the Black population, 9.6 (IQR, 5.7-12.6) to 20.9 (IQR, 12.1-32.8) among the Asian, Native Hawaiian, or Other Pacific Islander population, 9.6 (IQR, 6.9-11.6) to 19.1 (IQR, 11.6-24.9) among the Hispanic population, and 9.4 (IQR, 7.4-11.4) to 26.3 (IQR, 20.3-33.3) among the White population. In each year between 1999 and 2019, the Black population had the highest median state MMR. The American Indian and Alaska Native population had the largest increases in median state MMRs between 1999 and 2019. Since 1999, the median of state MMRs has increased for all racial and ethnic groups in the US and the American Indian and Alaska Native; Asian, Native Hawaiian, or Other Pacific Islander; and Black populations each observed their highest median state MMRs in 2019.

Conclusion and relevance: While maternal mortality remains unacceptably high among all racial and ethnic groups in the US, American Indian and Alaska Native and Black individuals are at increased risk, particularly in several states where these inequities had not been previously highlighted. Median state MMRs for the American Indian and Alaska Native and Asian, Native Hawaiian, or Other Pacific Islander populations continue to increase, even after the adoption of a pregnancy checkbox on death certificates. Median state MMR for the Black population remains the highest in the US. Comprehensive mortality surveillance for all states via vital registration identifies states and racial and ethnic groups with the greatest potential to improve maternal mortality. Maternal mortality persists as a source of worsening disparities in many US states and prevention efforts during this study period appear to have had a limited impact in addressing this health crisis.

Figure 1.. Maternal Mortality Ratios (MMRs) by State for 5 Racial and Ethnic Groups and the Total US Population, 2019

The color gradient shows MMRs by state in 2019 for 5 mutually exclusive, collectively exhaustive statistical racial and ethnic groups (A-E) and for the total US population (F). MMR values ranged from 0.5 to 300.8 and are in eTable 3 in Supplement 2. In 2019, there were an estimated 1210 total maternal deaths and 3 750 000 live births in the US. The number of maternal deaths and births by region and racial and ethnic groups are in the Table. State-level MMR estimates for 1999 are in eFigure 2 in Supplement 2. The map depicts geographic area; Alaska and Hawaii are not shown to scale.

Figure 2.. Percentage Change in Maternal Mortality Ratios (MMRs), 1999-2009 to 2010-2019

The color gradient shows percentage change in MMRs by state between the means of 2 10-year periods (A-E). The scatterplot shows mean MMRs by state and racial and ethnic group for 2 10-year periods with MMRs estimated using the aggregate of all deaths and births in each period for each state and racial and ethnic group (F).

Figure 3.. Distribution of State-Level Maternal Mortality Ratios (MMRs) by Year for 5 Racial and Ethnic Groups, 1999-2019

Box and whisker plots show the distribution of state MMRs by year. The boxes show the medians and IQRs of the distribution of state MMR values for each year and group. Whiskers show the distribution to 1.5 times above and below the IQR for each year and group. More extreme values (state MMR values greater than 1.5 times the IQR) are not depicted. Actual values are presented in eTable 5 in Supplement 2. National estimates of deaths, births, and MMRs are presented in the Table. Death and birth estimates, respectively, were 74 and 764 000 in 1999 and 184 and 887 000 in 2019 for the Hispanic population; 7 and 37 800 in 1999 and 23 and 33 300 in 2019 for the American Indian and Alaska Native population; 17 and 178 000 in 1999 and 56 and 269 000 in 2019 for the Asian, Native Hawaiian, or Other Pacific Islander population; 186 and 593 000 in 1999 and 393 and 581 000 in 2019 for the Black population; and 220 and 2 390 000 in 1999 and 551 and 1 980 000 in 2019 for the White population.