About Maternal Morbidity and Mortality

Research shows that maternal mortality—deaths related to pregnancy or giving birth—in the United States has increased in recent years and that U.S. rates are the highest among high-resource countries.1 Data also show that African American and American Indian/Alaska Native women are more likely than other U.S. groups to die from pregnancy, childbirth, or postpartum complications.2

For each woman who dies, many more women experience short- and long-term health problems related to pregnancy or giving birth, called maternal morbidity.3

To understand maternal morbidity and mortality, it’s important to know how different groups measure these issues and what the different terms mean.

Maternal Morbidity

Maternal morbidity describes unexpected short- or long-term health problems that result from being pregnant or giving birth. Some common conditions are cardiovascular disease, infection, bleeding, high blood pressure, and blood clots.4 These problems require additional medical care, such as hospitalization and long-term rehabilitation, and can affect a woman’s quality of life.5

Maternal morbidity can include near-miss cases, meaning women almost die from pregnancy or giving birth but survive.6 Some women who have near-misses are left with serious lifelong health problems and disabilities. Near-miss cases are sometimes counted separately from general maternal morbidity.

Severe maternal morbidity (SMM) describes life-threatening health problems that are present at delivery. Researchers use 18 indicators, such as kidney failure and fluid in the lungs, to measure SMM. An NICHD-funded study examined changes in U.S. SMM rates and indicators.

Maternal Mortality

The short answer to “What is maternal mortality?” is that it is a measure of deaths related to pregnancy and giving birth. The longer answer is that researchers and healthcare providers use different methods to track these deaths and different terms to describe them. Some of these terms include the following:

  • Maternal mortality or death refers to deaths that occur during pregnancy or within 6 weeks after the pregnancy ends that are related to pregnancy or its management.7 The World Health Organization (WHO) uses this description to report worldwide statistics.
  • Pregnancy-related deaths refers to deaths during pregnancy and up to 1 year after the pregnancy ends that are related to pregnancy or pregnancy care.1 The Centers for Disease Control and Prevention (CDC) often uses this measure to report statistics for the United States. It also reports on maternal mortality using the WHO description.
  • Pregnancy-associated deaths includes death during or in the year following pregnancy from causes not related to pregnancy, such as vehicle accidents, homicide, and suicide.7,8,9 An NICHD-funded study showed that homicide is a leading cause of pregnancy-associated death in Louisiana.

More research is needed to better understand the causes of these problems and deaths, the situations that contribute to them, and how to prevent them.
NICHD conducts and supports research on many pieces of the maternal morbidity and mortality puzzle.

  • Read this blog from NICHD Director Diana W. Bianchi, M.D., on the ways NICHD continues to advance women’s health and reduce maternal morbidity and mortality.
  • Check out this podcast with NICHD researcher Juanita Chinn, Ph.D., to learn more about maternal morbidity and mortality and NICHD’s efforts to understand them.

Citations

  1. Centers for Disease Control and Prevention (CDC). (2020). Pregnancy Mortality Surveillance System. Retrieved March 3, 2020, from https://www.cdc.gov/maternal-mortality/php/pregnancy-mortality-surveillance.
  2. CDC. (2017). Meeting the challenges of measuring and preventing maternal mortality in the United States. Retrieved January 14, 2020, from https://www.cdc.gov/grand-rounds/pp/2017/20171114-maternal-mortality.html.
  3. Geller, S. E., Koch, A. R., Garland, C. E., MacDonald, E. J., Storey, F., & Lawton, B. (2018). A global view of severe maternal morbidity: Moving beyond maternal mortality. Reproductive Health, 15, 98. Retrieved March 3, 2020, from https://reproductive-health-journal.biomedcentral.com/articles/10.1186/s12978-018-0527-2 external link.
  4. Chakhtoura, N., Chinn, J. J., Grantz, K. L., Eisenberg, E., Dickerson, S. A., Lamar, C., & Bianchi, D. W. (2019). Importance of research in reducing maternal morbidity and mortality rates. American Journal of Obstetrics and Gynecology, 221(3), 179–182. Retrieved March 3, 2020, from https://www.doi.org/10.1016/j.ajog.2019.05.050 external link.
  5. CDC. (2017). Severe maternal morbidity in the United States. Retrieved January 14, 2020, from https://www.cdc.gov/maternal-infant-health/php/severe-maternal-morbidity.
  6. Roopa, P. S., Verma, S., Rai, L., Kumar, P., Pai, M. V., & Shetty, J. (2013). “Near miss” obstetric events and maternal deaths in a tertiary care hospital: An audit. Journal of Pregnancy, 2013, 393758. Retrieved March 3, 2020, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3710620/.
  7. World Health Organization. (2020). Maternal mortality ratio (per 100 000 live births). Retrieved January 14, 2020, from https://www.who.int/data/gho/indicator-metadata-registry/imr-details/26 external link.
  8. CDC. (2019). Preventing pregnancy-related deaths. Retrieved March 3, 2020, from https://www.cdc.gov/maternal-mortality/preventing-pregnancy-related-deaths.
  9. CDC. (2019). Pregnancy-related deaths: Data from 14 U.S. Maternal Mortality Review Committees, 2008–2017. Retrieved March 3, 2020, from https://www.cdc.gov/maternal-mortality/php/erase-mm.
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