Maternal mortality data have not been included in final mortality reports as official statistics since 2007. This is due to staggered implementation over time of the 2003 revised death certificate by states, which includes the use of a new method to better identify maternal deaths. As a result, national data on maternal mortality have not been available. The publication of an official maternal mortality rate for the United States will resume with the release of 2018 final mortality data, along with a detailed analysis of the changes in collection methods and their impact on maternal mortality data.
(Adapted from the Technical Notes of National Vital Statistics Report, Vol. 68, No. 9, Deaths: Final Data for 2017 pdf icon[PDF – 1.8 MB],” released June 24, 2019)
The 2003 revision of the U.S. Standard Certificate of Death introduced a checkbox question format with categories to take advantage of additional codes available in the International Classification of Diseases, 10th Revision for deaths with a connection to pregnancy, childbirth, and the puerperium. As states revise their death certificates, most are adopting the checkbox format, resulting in wider adoption of a pregnancy status question nationwide and greater standardization of the particular question used.
In 2017, the District of Columbia and all states had a separate question (West Virginia adopted a separate question midyear) related to the pregnancy status of female decedents around the time of their death. The 2003 standard format of the question, or a question that could provide comparable information, was used by 48 states and the District of Columbia for the full year and by West Virginia for part of the year.
The question used by California only specifies if pregnant within the last year. Unlike the format used in the other states, it does not indicate detail on whether pregnant at the time of death, pregnant 42 days before death, or pregnant 43 days to 1 year before death.
Adopting a pregnancy status question consistent with the standard death certificate increases the identification of maternal deaths. Maternal mortality rates are consistently greater for those states with the additional information from the separate question than for the states without it. In addition, state maternal mortality rates tend to be greater after adopting the standard question than before.
Some research on this issue indicates that this increase represents an improvement in identifying maternal deaths. For example, a study pdf icon[PDF – 231 KB]external icon in Maryland that used multiple data sources as the standard showed an improvement in identifying maternal deaths (from 62% to 98%) after adoption of a pregnancy checkbox item consistent with the 2003 standard certificate.
However, growing evidence suggests the pregnancy status question may increase false reporting of recent pregnancy, especially with increasing age. This may result in overreporting of maternal deaths.
More data: reports and tables
- 2007 NCHS Methods Report pdf icon[PDF – 488 KB]: Hoyert DL. Maternal mortality and related concepts. National Center for Health Statistics. Vital Health Stat 3(33). 2007.
- CDC Pregnancy Mortality Surveillance System
- CDC Division of Reproductive Health, Study of Data Qualityexternal icon: Catalano A, Davis NL, Petersen EE, Harrison C, Kieltyka L, You M, et al. Pregnant? Validity of the pregnancy checkbox on death certificates in four states, and characteristics associated with pregnancy checkbox errors. Am J Obstet Gynecol. 2019 [In press].