Over the past two decades, the US maternal mortality rate has doubled, making the US the only developed nation in the world with an increasing maternal mortality rate. Specifically, non-Hispanic black women in the US are three to four times more likely to die from a pregnancy-related death than non-Hispanic white women. The issue is that maternal mortality data quality, timeliness, and access are limited. Nevertheless, maternal mortality is devastating and deserves attention.

What does existing data suggest are the causes of increased maternal mortality rates? The answer is complicated, influenced by many factors including prevalence of severe comorbidities, including chronic diseases; disparate provision of and access to care; racial and ethnic disparities; maternal age at time of pregnancy; and various social factors such as income, housing, and education. Research suggests that the increase in maternal mortality may be “an artifact of improvements in surveillance and highlight past underestimation of maternal death.” For example, the addition of a pregnancy status checkbox on death certificates in states that have adopted it may lead to increased identification of cases and errors in categorizing maternal mortality.

To better understand and begin to reduce maternal mortality in the United States, there is a need for consistent, reliable collection, storage, and dissemination of data, including health care data. Public reporting of health care data can enable hospital and clinician comparisons of performance metrics to drive quality improvement efforts; and empower patients to select hospitals and clinicians based upon performance outcomes. Such comparison and empowerment can improve the health outcomes of mothers and their newborn children.

Maternal Mortality And Maternal Health Data Sources

Currently, maternal mortality data are collected, stored, and shared via several federal, state, and local sources including but not limited to the Centers for Disease Control and Prevention (CDC), state health departments, and private health care systems. For example, through the Pregnancy Mortality Surveillance System (PMSS), the CDC collects and codes data regarding pregnancy-related deaths and associated risk factors from 50 states, New York City, and Washington, D.C. Although the PMSS is a centralized reporting system, reporting from jurisdictions is not mandatory. The data must be complete at the state level to feed into the national system. Moreover, due to the CDC’s interpretations of Section 308(d) Assurance of Confidentiality under the Public Health Service Act, the use of the data from PMSS is limited.

The collection of vital records data—such as births, deaths, marriages, divorces, and fetal death certificates—is similarly a state function. Vital records data, collected by the 57 vital records jurisdictions, are submitted to the CDC’s National Center for Health Statistics (NCHS) via a contract between NCHS and the jurisdictions. These data are then made available through restricted and public use mortality data files, and through the National Death Index (NDI). Restricted use files are available through the CDC Research Data Center, and de-identified public use files are available on the CDC Wide-ranging Online Data for Epidemiologic Research (WONDER) online databases. The NDI, which charges for data linkage, is intended for researchers who have Institutional Review Board approval, and who have a specific cohort of consented subjects to which they want to link the NDI mortality data files. The NDI consists of identified data for all deaths that have occurred in the US since 1979.

Despite reported increases in maternal mortality rates and the potential for Maternal Mortality Review Committees to identify causes, a 2017 study published in Obstetrics & Gynecology identified that only 29 of the 50 states currently have such committees. Although there are periodic initiatives between the CDC and states to collate and publish cohorts of data, such as Building U.S. Capacity to Review and Prevent Maternal Deaths, these reports do not provide a comprehensive state of maternal mortality in the US. Mark Thomas, PhD, executive director for Population Health and Wellbeing at the MITRE Corporation, noted that “the US health system is awash in data, but unless key maternal health variables are standardized and aggregated at the national level, we will continue to be in the dark about what is or isn’t effective against maternal deaths and health disparities.”  

Lessons Learned From California’s Efforts

Even as the national maternal mortality rates increase, California has decreased maternal mortality rates in that state by 55 percent over seven years through a series of initiatives led by public-private partnerships. Together, the California Department of Public Health and the California Maternal Quality Care Collaborative focused on three major components: research gathered from the California Pregnancy-Associated Mortality Review (CA-PAMR), the development of quality improvement toolkits based upon the CA-PAMR findings, and the creation of a maternal data center used by 90 percent of California’s hospitals. The underlying factor to California’s successful reduction of its maternal mortality rate is the creation of a comprehensive maternal-infant data set and the use of data-driven decision making. The nation can benefit from California’s efforts, by adopting and applying lessons learned across the country.

What Data Are Needed

At the MITRE Corporation, we are using CDC WONDER, Institute for Health Metrics and Evaluation, and Healthcare Cost and Utilization Project data to develop a tool to analyze how the application of California’s maternal care programming and budget affects maternal mortality rates among non-Hispanic black women. The aim is for policy makers to use this tool to determine cost of programming to reduce national rates of maternal mortality and the maternal mortality racial disparity. However, the challenge is that this tool must be validated to be useful, and the following data points are not currently available: 

• A source of continuous data outlining the maternal mortality rate per state, per year.
• Number of women of childbearing age per state, per year. Currently, only national numbers are available.
• The cost of maternal care, per person, per state, per year. 

Federal Action

Concern and alarm over reported increases in maternal mortality have spurred action by Congress in the form of $12 million in funding to support states’ maternal mortality review efforts. US Representative Jaime Herrera Beulter (R-WA) recognized the need for maternal data in the fight to reduce maternal mortality through the introduction of HR1318—Preventing Maternal Deaths Act of 2017 on March 2, 2017. The bill was passed in both the House and Senate unanimously and was signed into law by the president on December 21, 2018.

What’s Next

The new law directs the Department of Health and Human Services to establish a program that will support state efforts to:

• Establish or expand maternal mortality review committees;
• Collect consistent, standardized data;
• Work with the state Department of Public Health on maternal mortality prevention strategies; and
• Eliminate maternal mortality disparities.

There is national momentum to reduce maternal mortality and support state and national efforts to standardize data that will enable state-to-state and national comparisons, learnings, and data sharing. Building upon past successes and sharing future capabilities and strategies with common data can both reduce maternal mortality nationally and reduce the disparities that continue to persist.