Maternal Mortality Data in the US Revealed

Based on data from 36 states on 1,018 pregnancy-related deaths from 2017 to 2019, the CDC concluded that about a third of these occurred during pregnancy or on the day of delivery and that roughly another third before the baby was six months old.

30 percent occurred from that moment until the baby’s first year of life, a period in which research on maternal mortality had not focused.

Maternal Mortality Review Committees (MMRCs) are multidisciplinary committees that meet at the state or local level to comprehensively review deaths during or within one year of pregnancy (pregnancy-associated deaths). MMRCs have access to clinical and non-clinical information (e.g., vital records, medical records, social services records) to better understand the circumstances surrounding each death, determine whether the death was related to pregnancy, and develop management recommendations. action to prevent similar deaths in the future.

Data on 1,018 pregnancy-related deaths among residents of 36 states between 2017 and 2019 were shared with CDC through the Maternal Mortality Review Information Application (MMRIA).

Table 1 . Characteristics of pregnancy-related deaths, data from Maternal Mortality Review Committees in 36 US states, 2017-2019 (N=1,018) *

Among deaths for which the timing in relation to pregnancy is known:

• Approximately 22% of deaths occurred during pregnancy.
   
• 25% occurred on the day of delivery (within 24 hours of the end of pregnancy) or within a week of delivery.
   
• 23% occurred from 7 to 42 days postpartum.
   
• 30% occurred in the late postpartum period (43–365 days postpartum, Table 3).

Among pregnancy-related deaths with geographic information on place of residence (n=873), approximately 82% of those who died lived in urban areas.

Table 2 . Urbanicity of place of last residence, data from Maternal Mortality Review Committees in 36 US states, 2017-2019.

Among pregnancy-related deaths with information on place of last residence, 82% of those who died lived in urban counties .

Table 3 . Distribution of pregnancy-related deaths by timing of pregnancy-related death, data from Maternal Mortality Review Committees in 36 US states, 2017-2019.*

Among pregnancy-related deaths with timing information, 53% occurred 7 to 365 days after delivery.

Among the 1018 pregnancy-related deaths, an underlying cause of death was identified for 987 deaths. The 6 most common underlying causes of pregnancy-related death:

1. Mental health conditions (22.7%)
2. Hemorrhage (13.7%)
3. Heart and coronary conditions (12.8%)
4. Infection (9.2%)
5. Thrombotic embolism (8.7%)
6. Cardiomyopathy (8.5%)

They accounted for more than 75% of pregnancy-related deaths (Table 4).

The leading underlying cause of death varied by race and ethnicity. Heart and coronary conditions were the leading underlying cause of pregnancy-related deaths among non-Hispanic blacks; mental health conditions were the leading underlying cause of death among Hispanics and non-Hispanic whites; and bleeding was the leading underlying cause of death among non-Hispanic Asians.

Table 4 . Underlying causes of pregnancy-related deaths*, overall and by race and ethnicity 1, data from Maternal Mortality Review Boards in 36 US states, 2017-2019.

For each death, MMRCs determine whether the death was a suicide and whether the death was a homicide. Among the 1018 pregnancy-related deaths, a manner of death determination for suicide was available for 971 deaths and a manner of death determination for homicide was available for 1001 deaths. Undetermined deaths include those in which the MMRC selected unknown due to insufficient information or lack of agreement among committee members. Among pregnancy-related deaths with a determination, 82 (8.4%) were determined as suicide and 29 (2.9%) as homicide (Table 5).

Table 5 . Among pregnancy-related deaths, manner of death determined by the Maternal Mortality Review Committee, data from Maternal Mortality Review Committees in 36 US states, 2017-2019*

Among the 1,018 pregnancy-related deaths, a prevention determination was made for 996 deaths.

Among these, 839 (84%) were determined to be preventable (Table 6).

Table 6 . Percentage of pregnancy-related deaths determined by MMRCs to be preventable, data from Maternal Mortality Review Committees in 36 US states, 2017-2019.*

Definitions

Pregnancy-related : A death during pregnancy or within one year of the end of pregnancy due to a complication of pregnancy, a chain of events initiated by pregnancy, or the aggravation of an unrelated condition by the physiological effects of pregnancy. In addition to being temporally related to the pregnancy, these deaths are causally related to the pregnancy or its management.

Preventability : A death is considered preventable if the committee determines that there was at least some chance of preventing the death through one or more reasonable changes in patient, community, provider, facility, and/or systems factors. MMRIA allows MMRCs to document prevention decisions in two ways: (1) determining prevention as yes or no, and/or 2) determining the possibility of altering the outcome by using a scale indicating no possibility, some possibility or good possibility. We considered any death with an affirmative response or a response that there was some chance or a good chance of altering the preventable outcome. Deaths without response or without possibility were considered non-preventable .