There are two main sources for national estimates of maternal mortality: the National Center for Health Statistics (NCHS) and the Pregnancy Mortality Surveillance System (PMSS), both administered by the Centers for Disease Control and Prevention (CDC). NCHS and the World Health Organization (WHO) define maternal mortality as the death of a woman while pregnant or within 42 days of termination of pregnancy, regardless of the duration and the site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes. They express their findings as the maternal mortality rate, that is, the number of maternal deaths per 100,000 live births. NCHS has not published a national maternal mortality rate for the United States since 2007. PMSS expands the definition to include deaths within one year of delivery. In 2012, it expressed its findings as the pregnancy-related mortality ratio, that is, the number of pregnancy-related deaths per 100,000 live births.
NCHS and PMSS are valuable data sources for the surveillance of maternal mortality. They provide basic information about the causes of death of women during pregnancy and postpartum, and their associated risk factors. However, this national-level surveillance can’t point to specific factors that contributed to individual deaths, it doesn’t determine whether the death could have been prevented, and it can’t document opportunities from individual cases in order to act to prevent further occurrences of maternal mortality. It is for these reasons that state or jurisdiction-wide maternal mortality review committees (MMRCs) are so vital to the prevention of maternal mortality.
Maternal mortality review is a standard and comprehensive system primarily operating at the state level. MMRCs identify, review, and analyze maternal deaths; disseminate findings; and act on the results.
A MMRC gathers extensive information about each individual case of maternal death selected for review, and this information is synthesized into a story for that case. The committee convenes to further fill in the story and, for each case, answer the question, “What happened?” The committee then determines if the death was related to or aggravated by pregnancy. If so, the death is one counted in the state’s pregnancy-related mortality ratio. Committee members also will craft recommendations specific to the case to ensure that a similar story doesn’t unfold in the future.
Maternal mortality review has existed in the United States for more than a century. Originally, these committees were composed primarily of medical professionals, particularly obstetricians. Today, MMRCs have expanded their membership to include a vast array of professionals and partners engaging with and serving women during pregnancy and the year postpartum. Collectively, they examine patient/family, community, provider, facility, and system factors that lead to a woman’s death. The goal of maternal mortality review is not merely to prevent maternal death, but to put in place recommendations for actions that support health and wellness during pregnancy, childbirth, and postpartum.