Maternal Morbidity and Mortality

As we march into spring, the Department of Health and Human Services (HHS) and the National Institutes of Health (NIH) are enhancing their coordinated activities to address the problem of maternal morbidity and mortality.

In a wealthy nation like the United States, a healthy pregnancy and childbirth should be the norm, but  every 12 hours, a woman dies from complications from pregnancy or giving birth, according to the Centers for Disease Control and Prevention (CDC). Black and American Indian/Alaska Native women are about three times as likely to die from a pregnancy-related cause, compared to white women. Research also shows that up to 60 percent of these deaths are preventable.

The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) along with the Office of Research on Women’s Health (ORWH) and the Office of the NIH Director, is co-leading the Task Force on Maternal Mortality.  Our goal is to fund research that will reduce the rates of life-threatening complications during pregnancy, labor and delivery, and the postpartum period. The task force is developing two initiatives that NIH Director, Francis Collins, M.D., will present to an NIH-wide meeting this month:

• A community-based participatory research project that addresses equity in care
• A project to identify biomarkers for risk of morbidity and mortality during and after pregnancy

In addition, the Surgeon General’s office is working on an action plan on maternal health to identify programs in states and communities that have successfully reduced rates of maternal morbidity and mortality. NIH will advise the Surgeon General’s office, as well as HHS, on research to inform these plans.

Research Response

NICHD continues its deep commitment to maternal health, specifically with research to understand and address the increasing U.S. rates of life-threatening complications around pregnancy. NICHD funds more than 65 percent of NIH research on specific conditions related to maternal morbidity and mortality.

Soon, NICHD and other NIH institutes will begin analyzing responses from a recent Request for Information (RFI) that invited comments and suggestions for a proposed research initiative to decrease maternal mortality. The deadline for comments was late February. We look forward to integrating the feedback into our research plans.

Upcoming Workshops

Continuing our collaborative efforts, NICHD and the NIH ORWH are co-hosting a workshop in May to examine Pregnancy and Maternal Conditions that Increase the Risk of Morbidity and Mortality. The two-day workshop, also sponsored by the National Health, Lung, and Blood Institute and NIH’s Office of Disease Prevention, will bring together clinicians and researchers to discuss health conditions that can contribute to a complicated pregnancy, including hypertension, cardiovascular disease and preeclampsia. Registration for this workshop will open at the end of the month. It builds on two NICHD-led meetings in 2019: a community-engagement forum and a scientific workshop focused on health system and structural factors, measurement practices, and social determinants that affect maternal mortality and severe maternal morbidity.

Our 6th annual Human Placenta Project meeting also is scheduled for May. The meeting is an opportunity for scientists, clinicians, and patients to focus on this least understood—and arguably one of the most important—human organs, not only for the health of the woman and her fetus during pregnancy, but also for their lifelong health.

Other Activities

Other current NICHD activities aimed at improving health during and after pregnancy include the following:

• The Task Force on Research Specific to Pregnant Women and Lactating Women (PRGLAC) completed its second phase in February. The task force, established by the 21st Century Cures Act, now is leading an implementation plan for 15 recommendations submitted to the HHS secretary last year.
• PregSource^®: Crowdsourcing to Understand Pregnancy is a research project that aims to improve our understanding of pregnancy by gathering information directly from pregnant women through confidential online questionnaires. It is now is available in Spanish.
• Pregnancy for Every Body, is a new initiative that aims to educate plus-size pregnant women about healthy pregnancy and the importance of working with a healthcare provider to develop a pregnancy plan. Despite increased health risks, most plus-size women can have a healthy pregnancy and a healthy baby with regular prenatal care and monitoring by a healthcare provider.
• Birth Settings Study , supported by NICHD through the National Academy of Sciences, describes the impact of different birth settings and other social factors on maternal morbidity and mortality.

As I have said in this space before, any maternal death is one too many. I encourage women to get care as early in pregnancy as possible and to discuss their health and habits with their providers. In turn, providers (including non-obstetricians) should take a health history that includes recent pregnancies and listen to women, especially if they have health factors that increase the risk of post-partum complications. NICHD and NIH will continue to advance research to help ensure healthy pregnancies and lifelong wellness.

Select the image to read more about this infographic.

The United States experiences about 700 maternal deaths each year, and American Indian/Alaska Native and Black women are 2 to 3 times more likely to die from a pregnancy-related cause than white women. The Centers for Disease Control and Prevention (CDC) estimates that two-thirds of maternal deaths may be preventable.¹ Thousands more suffer from near misses or severe morbidity.

Maternal health is a priority for multiple NIH institutes that have heavily invested in research to prevent morbidity and mortality and improve overall health. In the past year, with base funding of $223 million,² NIH has worked across its Institutes, Centers, and Offices (ICOs) and with federal and community partners to support research to reduce preventable causes of maternal deaths and improve health for women, before, during, and after pregnancy. In a year that was dominated by both the COVID-19 pandemic and renewed calls to understand and resolve health disparities and inequities, NIH ensured these challenges were integrated into our efforts to reduce MMM.

Select a link to learn more:

• Generating Evidence to Change Practice and Save Lives through NIH-Supported Research
• Emphasizing Community Engagement
• Pivoting to Address COVID-19
• Looking to the Horizon
• Resources

Generating Evidence to Change Practice and Save Lives through NIH-Supported Research

• Minority women tend to deliver disproportionately in hospitals with lower quality ratings; however, evidence shows that initiatives targeted at quality improvement can substantially improve outcomes.³
• Risk of death during pregnancy and up to 1 year postpartum is significantly elevated among women residing in maternity care "deserts," which are counties that lack hospitals with obstetric care or midwives. Identifying and transporting women with high-risk pregnancies to facilities equipped for specialized care can mitigate MMM risks.⁴
• Homicide was identified as a leading cause of pregnancy-associated death. Increased contact with the healthcare system during pregnancy provides clinicians with an opportunity to offer potentially life-saving violence prevention services and interventions.⁵
• Women facing eviction from their homes while they were pregnant are more likely to have poor birth outcomes. Thus, providing housing, social, and medical assistance to pregnant women at risk for eviction may improve infant health.⁶

Emphasizing Community Engagement

Tackling the challenge of reducing MMM requires strong partnerships with and among local communities and resources, particularly with racial and ethnic minority populations that experience stark health disparities. To that end, several ICOs held community engagement activities to hear first-hand how patient communities can inform future research and what engagement strategies might enhance local efforts to improve maternal health.^7,8,9 A common refrain was that research conducted in a community should be developed with and vetted by the community to ensure success and improved outcomes. These engagement activities informed the development of NIH’s IMPROVE (Implementing a Maternal health and PRegnancy Outcomes Vision for Everyone) initiative, which aims to build an evidence base that will improve maternal care and outcomes from pregnancy through one year postpartum.¹⁰

Pivoting to Address COVID-19

As COVID-19 ravaged the country in early 2020, research increasingly showed that pregnant women were at higher risk for severe disease, including hospitalization, need for intensive care unit monitoring, and mechanical ventilation. NIH research showed that pregnant COVID-19 patients with severe disease are at higher risk for cesarean delivery, postpartum hemorrhage, hypertensive disorders of pregnancy, and preterm birth.¹¹ These findings come from the Gestational Research Assessments for COVID-19 (GRAVID) study, which evaluated data from more than 1,200 pregnant women at 33 hospitals across the country. Additional research on maternal health related to COVID-19 includes:

• Developing Common Data Elements that can be used in any study involving pregnant women, facilitating data analysis across different research studies¹²
• Evaluating the effects of remdesivir in pregnant women being treated with the drug for COVID-19¹³

Looking to the Horizon

NIH is accelerating research on factors that affect pregnancy-related and pregnancy-associated morbidity and mortality to improve care and outcomes. NIH’s Fiscal Year 2020 investments included:

• Supplements to expand existing research projects or support pilot projects for community-partnered research to resolve health disparities, strengthen evidence-based care and improve outcomes, and explore comorbidities to identify preventable risk factors and develop effective early interventions¹⁴
• "Addressing Racial Disparities in Maternal Morbidity and Mortality” funding opportunity to support research that tests clinical, social-behavioral, and healthcare system interventions to address racial disparities¹⁵ and needs of underserved women¹⁶
• Institutional Development Award (IDeA) States, created to expand research and research capability in states that have historically received low levels of NIH funding to address women’s health and maternal and infant morbidity and mortality¹⁷; reissued in Fiscal Year 2021¹⁸

Funding opportunities for Fiscal Year 2021 include:

• IMPROVE initiative supplements to add or expand research focused on the intersection of maternal health, structural racism, and discrimination, and how these were affected by the COVID-19 pandemic¹⁹
• Small Business Innovation Research and Small Business Technology Transfer (SBIR/STTR) awards to develop technologies or tools to quantitatively predict or indicate an increased risk for MMM²⁰
• Early Intervention to Promote Cardiovascular Health of Mothers and Children (ENRICH) for testing the effectiveness of an implementation-ready intervention designed to promote cardiovascular health (CVH) and address CVH disparities in marginalized birthing people and children in clinical or community sites²¹
• Partnership with CDC, the Patient-Centered Outcomes Research Trust Fund, and the Office of the National Coordinator for Health Information Technology to create standards to link electronic health record data on maternal and infant health for use in studying the effect of medical conditions and/or interventions on pregnant, postpartum, or lactating women and their infants²²
• Interdisciplinary community-engaged research to reduce or eliminate infections and sepsis as MMM causes²³

Resources

For additional information on NIH-supported MMM research and funding opportunities:

• NIH MMM Web Portal: https://orwh.od.nih.gov/womens-health-research/maternal-morbidity-and-mortality/welcome
• IMPROVE initiative: https://www.nih.gov/research-training/medical-research-initiatives/improve-initiative
• NICHD MMM website: https://www.nichd.nih.gov/health/topics/maternal-morbidity-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.

Certain factors increase a woman’s risk for maternal morbidity and mortality. In some cases, the woman and her healthcare provider may be able to change some of these factors to lower the risk. But not all factors can be changed. Additionally, some women experience maternal morbidity, severe maternal morbidity, near misses, or death without having any known risk factors.

Some factors that increase a woman’s risk for maternal morbidity and mortality include the following¹:

• Existing or pre-pregnancy health conditions, such as cardiovascular disease, obesity, asthma, or a compromised immune system
• Older maternal age
• Lifestyle factors, such as being a current or former cigarette smoker
• Having twins, triplets, or other multiples
• Certain pregnancy complications:
  • Preeclampsia, a spike in blood pressure after the 20th week of pregnancy, increases a woman’s risk for high blood pressure, blot clots, and stroke later in life.²
  • Women who have gestational diabetes, high blood sugar during pregnancy, are at higher lifetime risk for diabetes (usually type 2) and for fatty liver disease.^3,4
• Certain features of giving birth:
  • An NICHD-funded study found that first-time moms who delivered vaginally were at higher risk for pelvic floor disorders.
  • Although vaginal birth after cesarean (VBAC) is safe for some women, women who had certain types of incisions are at higher risk for rupture of the uterus, a rare but serious problem, during VBAC. A rupture can lead to infection, bleeding, and other problems.⁵
• Racial, ethnic, and socioeconomic backgrounds. Research shows disparities in the rates of maternal deaths in the United States, with black women and American Indian/Alaska Native women at highest risk for pregnancy-related death.

Many factors that increase a woman’s risk for maternal morbidity and mortality may also mean she has a high-risk pregnancy, one in which the mother, the fetus, or both are at higher risk for problems than a typical pregnancy. Healthcare providers may consider a pregnancy to be high-risk for reasons such as having twins or an existing health problem. Healthcare providers may adjust their care for a high-risk pregnancy to closely monitor the pregnancy.

Having one or more of these risk factors does not mean that a woman is certain to have health problems or that she will die during pregnancy or childbirth. Also, most women will not experience any complications in pregnancy.

Maternal morbidity includes a range of different health conditions. Some of them start during pregnancy and last only a short time, while others do not develop until years after a pregnancy and continue throughout the woman’s life.

Maternal mortality usually results from a pregnancy, delivery, or postpartum complication; a chain of medical events started by the pregnancy or delivery; the worsening of an unrelated condition because of the pregnancy or delivery; or other factors.¹

Maternal Morbidity

Maternal health problems related to pregnancy and giving birth can occur during pregnancy, during delivery, and after a pregnancy ends. Some common examples of maternal morbidity include the following²:

• Cardiovascular problems, such as heart disease and blood vessel problems
• Diabetes
• High blood pressure
• Infections, especially from cesarean section
• Blood clots
• Bleeding (sometimes called hemorrhage)
• Anemia (low iron in the blood)
• Nausea and vomiting (sometimes called morning sickness) and hyperemesis gravidarum (severe morning sickness)
• Depression and anxiety

The Centers for Disease Control and Prevention (CDC) uses International Classification of Disease codes and whether a woman is hospitalized to group examples of severe maternal morbidity (SMM). Some SMM examples include heart attack, heart failure, eclampsia, sepsis/blood infection, and hysterectomy.³ If a woman needs breathing assistance, such as a ventilator, or needs a blood transfusion, it is also considered SMM.

Maternal Mortality

According to the World Health Organization (WHO), the following cause the majority of maternal deaths around the world⁴:

• Severe bleeding (sometimes called hemorrhage)
• Infections
• Blood pressure disorders of pregnancy, including preeclampsia and eclampsia
• Complications of labor and delivery
• Unsafe abortion

Infections and chronic medical conditions, such as diabetes, are also causes of or associated with maternal deaths worldwide.

In the United States, CDC tracks pregnancy-related deaths, including deaths that WHO calls “maternal mortality.” The leading causes of pregnancy-related death in the United States, according to CDC, are slightly different than maternal mortality causes around the world.

In the United States, the main causes of pregnancy-related deaths include the following⁵:

• Severe bleeding (sometimes called hemorrhage)
• Infections and sepsis
• Cardiovascular conditions, such as:
  • Blockages (sometimes called embolisms) in arteries and veins
  • Stroke (also called cerebrovascular accidents)
  • Blood pressure disorders of pregnancy, including preeclampsia and eclampsia
  • Heart muscle problems (called cardiomyopathy)
  • Heart disease
• Problems with anesthesia
• Amniotic fluid embolism
• Non-cardiovascular conditions, such as diabetes and breathing problems

For more information on national trends and causes of pregnancy-related death, visit CDC: Pregnancy Mortality Surveillance System.

CDC also reports on pregnancy-associated deaths, from causes unrelated to pregnancy. Common causes of pregnancy-associated deaths include trauma (including motor vehicle accidents), homicide, suicide, and drug overdoses.^6,7,8

NICHD provides information on many topics relevant to maternal morbidity and mortality, including the following:

• Breastfeeding and breast milk
• Diabetes (including gestational diabetes)
• High-risk pregnancy
• HIV/AIDS
• Labor and delivery
• Obesity and overweight
• Pelvic floor disorders
• Pelvic pain
• Preeclampsia and eclampsia
• Pre-pregnancy care and prenatal care
• Pregnancy
• Pregnancy loss
• Preterm labor and birth
• Stillbirth
• Stroke
• Women’s health
• Zika

Find more resources about maternal morbidity and mortality.

It is hard to answer this question, because the causes of and situations surrounding maternal morbidity and mortality are complex. Because many factors play a role in maternal morbidity and mortality, there is no single way to prevent maternal health problems and deaths.

Improving maternal health could prevent many maternal deaths.¹ Knowing about risk factors allows healthcare providers and pregnant women to work together to watch before, during, and after the pregnancy and birth; identify problems; and take steps to fix problems before they become serious. Doing so may reduce the risk of long-term problems and prevent death. Some research suggests that the majority of maternal deaths may be preventable.¹

For example, NICHD launched its Pregnancy for Every Body initiative, which educates plus-size pregnant women about working with their healthcare provider to increase their chances of healthy pregnancy and delivery. Pre-pregnancy and prenatal care can also help reduce risks.

But not all problems can be detected before they become serious. Some problems and risks are not related to specific behaviors or chronic conditions and cannot be detected, prevented, or treated. In some cases, serious health problems and deaths may occur without any warning signs, meaning there is nothing a woman or her healthcare provider could do to prevent them.

Research that advances our understanding of pregnancy and childbirth eventually will help improve maternal healthcare, inform treatments, and potentially allow healthcare providers to identify and address complications before they become serious. Learn more at NICHD Maternal Morbidity and Mortality Research Information.

At the same time, healthcare providers, hospitals and health systems, families, and pregnant women are working to reduce maternal morbidity and mortality. Some of these activities include the following:

• Creating review committees to examine causes of maternal death
• Sharing safety checklists at hospitals, clinics, and provider offices
• Improving access to high-quality healthcare
• Alerting women about signs and symptoms of complications that could become serious

Worldwide, the majority of maternal deaths occur in developing countries, where women have little or no access to healthcare services.¹ Reducing maternal mortality and morbidity is a priority for many national departments of health and for international organizations, including the World Health Organization (WHO). Read more about WHO efforts to reduce maternal mortality and morbidity .