Maternal death rates nearly doubled in 2 decades, study finds. Inconsistent data collection also hampers improvement efforts

Maternal death rates more than doubled over the last two decades, with Black, American Indian and Native Alaskan women being particularly vulnerable to this trend, according to a study in JAMA Network.

While American Indian and Native American maternal death rates increased the most between 1999 and 2019, Black median mortality rates continued to be the highest overall.

Though experts agree that maternal mortality ratios (MMRs) contribute to the problem of racial and ethnic healthcare disparities in the United States, study researchers with the University of Washington note that a change in how to report maternal deaths makes it difficult to more precisely pinpoint the scope of the problem.

States began to add MMRs as a checkmark on death certificates between 2003 and 2017 and it’s possible that some of the increases in maternal morality found in the study could have resulted from this change in methodology, which different dates adopted in different years, and some states have yet to adopt.

“Efforts to understand U.S. maternal mortality trends over the past 20 years have been limited by inconsistent use of terminology, differences between states in how maternal death has been defined, and states’ differential timing of the addition of a U.S. standard pregnancy question (the ‘pregnancy checkbox’) to their death certificates,” the study states. “Some states, citing concerns for data integrity, have recently delayed release of their data, hampering policy and improvement efforts.”

Nonetheless, researchers conclude that U.S. comprehensive mortality surveillance in all states does a good enough job noting where maternal mortality increases and among which racial or ethnic groups. Because data on maternal deaths lack granularity within states and by race and ethnicity levels, particularly in less populous states, policymakers have had to rely on aggregate data reporting over multiple years and geographic regions. This, in turn, may have inhibited the development of timely interventions and policies.

“Using statistical models, MMRs in the current study were estimated for every state, year, and racial and ethnic group, providing a novel approach to understanding patterns of maternal mortality in the U.S.,” the study states. “Comprehensive estimates of maternal mortality may be useful for guiding policy decisions and for benchmarking progress in reducing disparities over time.”

Researchers collected data from pregnant or recently pregnant females aged 10 to 54 years old and defined maternal deaths as deaths occurring up to one year after the end of a pregnancy. This observational study mines data from the Census Bureau, and the National Vital Statistics System, overseen by the Centers for Disease Control and Prevention.

In 2019, MMRs across states were higher among American Indians and Alaska Natives and Blacks than among Asians, Native Hawaiians, or Other Pacific Islanders; Hispanics; and Whites. Between 1999 and 2019, median state MMRs increased from 14 to 49.2 per 100,000 individuals among American Indians and Alaska Natives; 26.7 to 55.4 among Blacks; 9.6 to 20.9 among Asians, Native Hawaiians, or Other Pacific Islanders; 9.6 to 19.1 among Hispanics; and 9.4 to 26.3 among Whites.

“In each year between 1999 and 2019, the Black population had the highest median state MMR,” the study states. “The American Indian and Alaska Native population had the largest increases in median state MMRs between 1999 and 2019.”

State healthcare panels find most maternal deaths to be avoidable and, therefore, prevention efforts must be guided by patterns that point to inequities within states.

“Additional investigation is needed to better understand what factors are contributing to increasing maternal mortality and how systemic racism, which is associated with broader social determinants of health and individual health characteristics, relates to persistent inequities in maternal mortality in the U.S. and how interventions to dismantle these structural barriers might improve outcomes.”