Pregnancy-Related Deaths: Data from 14 U.S. Maternal Mortality Review Committees, 2008-2017
Maternal Mortality Review Committees (MMRCs) are multi-disciplinary committees that convene at the state or local level to comprehensively review deaths of women during or within a year of pregnancy. MMRCs have access to clinical and non-clinical information (e.g., vital records, medical records, social service records) to more fully understand the circumstances surrounding each death, and to develop recommendations for action to prevent similar deaths in the future.
A total of 14 MMRCs voluntarily shared 2008-2017 data with CDC through the Maternal Mortality Review Information Application (MMRIA). Among 1,347 deaths to women during or within a year of pregnancy, a pregnancy-relatedness determination was made for 1,260 (93.5%). Among these, 454 (36.0%) were determined by the 14 MMRCs to be pregnancy-related.
- Table 1: Characteristics of pregnancy-related deaths
- Table 2: Distribution of pregnancy-related deaths by timing of death in relation to pregnancy
- Table 3: Leading underlying causes of pregnancy-related deaths, overall and by race-ethnicity
- Table 4: Percent of pregnancy-related deaths determined by MMRCs to be preventable, overall and by race-ethnicity
Data from the Maternal Mortality Review Information Application
- Approximately 1 in 3 deaths among women during or within a year of pregnancy were pregnancy-related.
- Pregnancy-related deaths occurred during pregnancy, delivery, and up to a year postpartum.
- Leading causes of pregnancy-related deaths varied by race/ethnicity.
- 2 out of 3 deaths were determined to be preventable.
Table 1. Characteristics of pregnancy-related deaths, data from 14 maternal mortality review committees, 2008-2017 (N=454)
|Age at death|
|High school or less||229||53.5|
|Associate or Bachelor degree||77||18.0|
*Race/ethnicity and age were missing for 13 (2.9%) pregnancy-related deaths; education was missing for 26 (5.7%) deaths
Approximately 24% of deaths occurred during pregnancy, 34% occurred on the day of delivery or within a week after delivery, 19% occurred between 7-42 days postpartum, and 24% occurred in the later postpartum period (43-365 days postpartum, Table 2).
Table 2. Distribution of pregnancy-related deaths by timing of death in relation to pregnancy, data from 14 maternal mortality review committees, 2008-2017.* N % During pregnancy 91 23.9 Day of delivery 59 15.5 1-6 days postpartum 70 18.4 7-42 days postpartum 71 18.6 43-365 days postpartum 90 23.6 *Specific timing information is missing for 73 (16.1%) pregnancy-related deaths
|Day of delivery||59||15.5|
|1-6 days postpartum||70||18.4|
|7-42 days postpartum||71||18.6|
|43-365 days postpartum||90||23.6|
Cardiovascular conditions†, hemorrhage, infection, embolism†, cardiomyopathy, mental health conditions§, and preeclampsia/eclampsia accounted for nearly 75% of pregnancy-related deaths (Table 3). In addition, there were at least 5 pregnancy-related deaths due to each of the following: amniotic fluid embolism (4.8%), cerebrovascular accidents (4.1%), unintentional injury (2.6%), homicide (2.1%), autoimmune diseases (1.9%), seizure disorders (1.9%), malignancies (1.7%), pulmonary conditions (1.7%), anesthesia complications (1.4%), blood disorders (1.4%), and metabolic or endocrine conditions (1.2%). The leading underlying causes of death varied by race/ethnicity. Cardiomyopathy and cardiovascular conditions were the two leading underlying causes of pregnancy-related deaths among non-Hispanic Black women. In contrast, the leading underlying cause of death among non-Hispanic White women was mental health conditions. There were not sufficient data to examine the leading causes of pregnancy-related deaths among Hispanic women.
Table 3. Leading underlying causes of pregnancy-related deaths, overall and by race-ethnicity, data from 14 maternal mortality review committees, 2008-2017.*
|Total||non-Hispanic Black||non-Hispanic White|
|Mental Health Conditions§||37||8.8||—||—||30||14.9|
|Preeclampsia and Eclampsia||35||8.3||18||11.4||13||6.5|
*Specific cause of death was missing or listed as “Unknown” for a total of 34 (7.5%) pregnancy-related deaths. Numbers are not presented when cell size is <5. Deaths among women not classified as non-Hispanic Black or non-Hispanic White are included in the total number of deaths.
†Cardiovascular conditions include deaths to coronary artery disease, pulmonary hypertension, acquired and congenital valvular heart disease, vascular aneurysm, hypertensive cardiovascular disease, Marfan Syndrome, Conduction defects, vascular malformations, and other cardiovascular disease; and excludes cardiomyopathy and preeclampsia, eclampsia, and chronic hypertension with superimposed preeclampsia which are categorized separately.
‡Embolism includes thrombotic pulmonary or other embolism (i.e., air, septic, or fat). It does not include amniotic fluid embolism.
- Mental health conditions include deaths to suicide, overdose/poisoning, and unintentional injuries determined by the MMRC to be related to a mental health condition.
Among the 454 pregnancy-related deaths, a preventability determination was made by the 14 MMRCs for 354 (78.0%). Among these, 233 (65.8%) were determined to be preventable (Table 4). The percent of deaths determined to be preventable did not significantly differ between non-Hispanic Black (63.0%) and non-Hispanic White (68.2%) women (p-value=0.4) nor between Hispanic (61.8%) and non-Hispanic White women (p-value=0.5).
Table 4. Percent of pregnancy-related deaths determined by MMRCs to be preventable, overall and by race-ethnicity, data from 14 maternal mortality review committees, 2008-2017.*
|# preventable||% preventable|
|*A preventability determination was missing (n=81) or unable to be determined (n=19) for a total of 100 (22.0%) pregnancy-related deaths.
†A total of 22 deaths among race-ethnicities not classified as Hispanic, non-Hispanic Black, or non-Hispanic white were also determined to be preventable.
Data shared by 14 state MMRCs through the maternal mortality review information application (MMRIA) were analyzed. MMRIA supports and standardizes record abstraction, case summary development, documentation of committee decisions, and routine analysis. Data shared included information on pregnancy-associated and pregnancy-related deaths that occurred between 2008 and 2017; Arizona (2016), Colorado (2008–2012, 2014-2015), Delaware (2009–2017), Florida (2017), Georgia (2012–2014), Hawaii (2015–2016), Illinois (2015), Louisiana (2017), Mississippi (2016–2017), North Carolina (2014–2015), Ohio (2008–2016), South Carolina (2014–2018), Tennessee (2017) and Utah (2014–2016). In some cases, only partial years of data may have been received.
We used race and ethnicity data from the birth certificate when available and from death certificates when a birth certificate was unavailable. Race and ethnicity were categorized consistent with Office of Management and Budget Race and Ethnic Standards for Federal Statistics and Administrative Reporting (Revisions 1997). However, available data did not support analysis beyond non-Hispanic white, non-Hispanic black and Hispanic groupings. Age at death was based on information from the death certificate. The timing of death in relation to pregnancy was calculated as the number of days between the date of death on the death certificate and the date of birth or fetal death on the linked birth or fetal death certificate. In addition, death certificates with the standard pregnancy checkbox marked as “Pregnant at the time of death” were used to indicate deaths that occurred during pregnancy. The percentage of deaths determined by MMRCs to have been preventable, as defined below, were calculated, and chi-squared tests were used to assess whether preventability significantly differed by race-ethnicity.
Pregnancy-Associated: The death of a woman during pregnancy or within one year of the end of pregnancy from a cause that is not related to pregnancy. All deaths that have a temporal relationship to pregnancy are included.
Pregnancy-Related: The death of a woman during pregnancy or within one year of the end of pregnancy from a pregnancy complication, a chain of events initiated by pregnancy, or the aggravation of an unrelated condition by the physiologic effects of pregnancy. In addition to having a temporal relationship to pregnancy, these deaths are causally related to pregnancy or its management.
Preventability: A death is considered preventable if the committee determines that there was at least some chance of the death being averted by one or more reasonable changes to patient, community, provider, facility, and/or systems factors. MMRIA allows MMRCs to document preventability decisions in two ways: 1) determining preventability as a “yes” or “no”, and/or 2) determining the chance to alter the outcome using a scale that indicates “no chance”, “some chance”, or “good chance”. Any death with a “yes” response or a response that there was “some chance” or a “good chance” to alter the outcome was considered “preventable”; deaths with a “no” response or “no chance” were considered “not preventable”.
Nicole Davis and David Goodman are with the National Center for Chronic Disease Prevention and Health Promotion, Division of Reproductive Health; Ashley Smoots is a CDC Foundation Field Employee assigned to the National Center for Chronic Disease Prevention and Health Promotion, Division of Reproductive Health.
Davis NL, Smoots AN, Goodman DA. Pregnancy-Related Deaths: Data from 14 U.S. Maternal Mortality Review Committees, 2008-2017. Atlanta, GA: Centers for Disease Control and Prevention, U.S. Department of Health and Human Services; 2019.
Maternal Mortality Review Committee data was provided by the Arizona, Colorado, Delaware, Florida, Georgia, Hawaii, Illinois, Louisiana, Mississippi, North Carolina, Ohio, South Carolina, Tennessee, and Utah Departments of Health or agencies responsible for maternal mortality review. Any published findings and conclusions are those of the authors and do not necessarily represent the official position of the Arizona, Colorado, Delaware, Florida, Georgia, Hawaii, Illinois, Louisiana, Mississippi, North Carolina, Ohio, South Carolina, Tennessee, or Utah Departments of Health or agencies responsible for maternal mortality review. We are also grateful to the Building U.S. Capacity to Review and Prevent Maternal Deaths Team at the Centers for Disease Control and Prevention, CDC Foundation, and the Association of Maternal and Child Health Programs; this work was supported in part by funding from Merck, through an award agreement with its Merck for Mothers Program, and through federal appropriations.