Racial and Ethnic Disparities in Maternal Mortality Persist in Many US States

Maternal mortality persists at inexcusably high rate among all racial and ethnic groups in the United States (US), but American Indian and Alaska Native and Black individuals are at amplified risk, especially in some states where attention has not been drawn to such inequities previously, according to a new study published in JAMA.¹

While prior evidence has suggested an increase in maternal mortality in the US, comprehensive estimates of long-term maternal mortality trends across US states have not been reported, the authors noted. The new study aimed to quantify trends in maternal mortality ratios (MMRs; maternal deaths per 100,000 live births) in all US states and across 5 mutually exclusive racial and ethnic groups.

“The US has a high rate of maternal mortality, compared with other high-income countries, despite spending more per person on health care,” the study authors wrote. Maternal mortality continues to be a source of worsening disparities in several US states, and prevention endeavors during this study period seem to have had an inadequate influence in tackling this health crisis.

Researchers found that median state MMRs for the American Indian and Alaska Native, Asian, Native Hawaiian, or Other Pacific Islander populations continued to grow, even after the integration of a pregnancy checkbox on death certificates, and median state MMR for the Black population continued to be the highest in the country.

Quantifying Maternal Mortality in US States

The observational study was conducted using vital registration and census data from 1999 to 2019 in the US. Pregnant or recently pregnant people from the ages 10 to 54 years were recorded.

The median of state MMRs has grown for all racial and ethnic groups in the US since 1999, and the American Indian and Alaska Native; Asian, Native Hawaiian, or Other Pacific Islander; and Black populations all saw their highest median state MMRs in 2019. Also in 2019, MMRs in most states were higher among American Indian and Alaska Native, and Black populations than for Asian, Native Hawaiian, or Other Pacific Islander; Hispanic; and White populations.

Between 1999 and 2019, the data showed that median state MMRs among the American Indian and Alaska Native population grew from 14.0 (IQR, 5.7-23.9) to 49.2 (IQR, 14.4-88.0). Among the Black population, median state MMRs increased from 26.7 (IQR, 18.3-32.9) to 55.4 (IQR, 31.6-74.5). In the Asian, Native Hawaiian, or Other Pacific Islander population, median state MMRs rose from 9.6 (IQR, 5.7-12.6) to 20.9 (IQR, 12.1-32.8). Among the Hispanic population, median state MMRs increased from 9.6 (IQR, 6.9-11.6) to 19.1 (IQR, 11.6-24.9), and among the White population they increased from 9.4 (IQR, 7.4-11.4) to 26.3 (IQR, 20.3-33.3).

The Black population had the highest median state MMR each year between 1999 and 2019, while the American Indian and Alaska Native population had the largest growth in median state MMRs in the same time frame.

"These disparities in maternal mortality are just the tip of the iceberg and tell us a lot about the health risks facing people in the states where these deaths are most likely to occur," Gregory A. Roth, MD, MPH, associate professor in the Division of Cardiology and director of the Program in Cardiovascular Health Metrics at the Institute for Health Metrics and Evaluation, said in a statement.² "In the US, maternal deaths are often caused by vascular diseases like severe high blood pressure or blood clots. So maternal deaths share many of the same drivers as heart attacks, strokes, and heart failure. Our state-by-state research emphasizes where we need to focus our prevention efforts and which groups are suffering the most."

State review comittees have determined that most maternal deaths are preventable, the authors noted. Thus, prevention efforts are vital and should account for patterns of maternal deaths and state inequities, the authors noted. Further investigation is necessary to understand the factors impacting the increase in maternal mortality, as well as the ways in which systemic racism and broader social determinants of health relate to the observed persistent inequities.

Several limitations were present in the study. Initially, some individuals might have been incorrectly classified by race and ethnicity on their death certificate. Secondly, the present study contains all maternal deaths but does not stratify according to the use of the US standard pregnancy question (the pregnancy checkbox) on death certificates.

"Maternal mortality is a crisis in the United States. These rates have been increasing over the past several decades and were exacerbated by the pandemic," co-first author Allison Bryant, MD, MPH, senior medical director for health equity at Mass General Brigham, said in a statement.² "Our study sheds light on the wide disparities within maternal mortality rates — the specter of maternal death differentially burdens some ethnic and racial populations."

References

1. Fleszar LG, Bryant AS, Johnson CO, et al. Trends in state-level maternal mortality by racial and ethnic group in the united states. JAMA. 2023;330(1):52-61. doi: 10.1001/jama.2023.9043

2. Maternal mortality in the US more than doubled between 1999 and 2019. News Release. Mass General Brigham; July 3, 2023. Accessed June 29, 2023. https://www.massgeneralbrigham.org/en/about/newsroom/press-releases/us-maternal-mortality-more-than-doubled-1999-to-2019