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Pregnancy-Related Mortality in California: Causes, Characteristics, and Improvement Opportunities

Main, Elliott K. MD; McCain, Christy L. MPH; Morton, Christine H. PhD; Holtby, Susan MPH; Lawton, Elizabeth S. MHS

doi: 10.1097/AOG.0000000000000746
Contents: Original Research

OBJECTIVE: To compare specific maternal and clinical characteristics and contributing factors among the five leading causes of pregnancy-related mortality to develop focused clinical and public health prevention programs.

METHODS: California pregnancy-related deaths from 2002–2005 were identified with enhanced surveillance using linked birth and death certificates. A multidisciplinary committee reviewed medical records, autopsy reports, and coroner reports to determine cause of death, clinical and demographic characteristics, chance to alter outcome, contributing factors (at health care provider, facility, and patient levels), and quality improvement opportunities. The five leading causes of death were compared with each other and with the overall California birth population.

RESULTS: Among the 207 pregnancy-related deaths, the five leading causes were cardiovascular disease, preeclampsia or eclampsia, hemorrhage, venous thromboembolism, and amniotic fluid embolism. Among the leading causes of death, we identified differing patterns for race, maternal age, body mass index, timing of death, and method of delivery. Overall, there was a good-to-strong chance to alter the outcome in 41% of deaths, with the highest rates of preventability among hemorrhage (70%) and preeclampsia (60%) deaths. Health care provider, facility, and patient contributing factors also varied by cause of death.

CONCLUSION: Pregnancy-related mortality should not be considered a single clinical entity. Reducing mortality requires in-depth examination of individual causes of death. The five leading causes exhibit different characteristics, degrees of preventability, and contributing factors, with the greatest improvement opportunities identified for hemorrhage and preeclampsia. These findings provide additional support for hospital, state, and national maternal safety programs.


The five leading causes of maternal mortality exhibit different clinical characteristics and degrees of preventability, with hemorrhage and preeclampsia demonstrating the greatest opportunities for improvement.

California Maternal Quality Care Collaborative, Stanford University, Palo Alto, California Pacific Medical Center, San Francisco, the Public Health Institute, Santa Cruz, the Department of Family and Community Medicine, University of California, San Francisco, School of Medicine, San Francisco, and the Maternal, Child and Adolescent Health Division, Center for Family Health, California Department of Public Health, Sacramento, California.

Corresponding author: Elliott K. Main, MD, CMQCC, Stanford University, 1265 Welch Road, MS 5415, Palo Alto, CA 94305; e-mail:

This project was made possible by Federal Title V MCH block grant funding from the California, Department of Public Health (CDPH), Maternal Child and Adolescent Health (MCAH) Division.

The authors thank the California Pregnancy-Associated Mortality Review Committee for their careful case reviews and Dr. Connie Mitchell, Deputy Director, CDPH Center for Family Health, and Dr. Shabbir Ahmad, Chief, MCAH Epidemiology, Assessment, and Program Development, for their ongoing support of the California Pregnancy-Associated Mortality Review project.

Financial Disclosure The authors did not report any potential conflicts of interest.

© 2015 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.