Skip Navigation LinksCA-PMSS

Maternal, Child and Adolescent Health Division

The California Pregnancy Mortality Surveillance System (CA-PMSS)

Maternal mortality is a key indicator of population health. Deaths in pregnancy and postpartum should be rare events, so routine and accurate surveillance of pregnancy-related deaths is an essential public health responsibility. CA-PMSS is a statewide surveillance of deaths among Californians who were pregnant within the prior year. The Maternal, Child and Adolescent Health (MCAH) Division of the California Department of Public Health (CDPH) initiated CA-PMSS in 2018 to provide a timely and accurate accounting of deaths related to or aggravated by the pregnancy or its management. In CA-PMSS, deaths are identified by complex data linkage of vital statistics data and patient-level administrative data from hospitals, emergency departments and ambulatory surgery centers. Coroner and autopsy reports and medical records are used to verify pregnancy status and timing to death. A committee of experts conducts limited case reviews of the deaths to determine the underlying cause of death and whether it was related to pregnancy.

The goal of CA-PMSS is to monitor deaths related to pregnancy using the most accurate information available. While the commonly used maternal mortality ratio (MMR) remains a key indicator of the overall health of a population, it relies solely on death certificate data. CA-PMSS compiles the findings from its more complex data linkage and expert committee review to create a pregnancy-related mortality ratio (PRMR), allowing California to monitor deaths related to pregnancy using the most accurate information available .

Here are the major differences between the two maternal mortality measures:

Major differences

Pregnancy-Related Mortality Ratio (PRMR) as used in CA-PMSS and CA-PAMR and by CDC RDH*

Maternal Mortality Ratio (MMR) as used by the CDC NCHS**

Time frame

Captures more maternal deaths by expanding the time frame up to one year after pregnancy.

Includes maternal deaths only up to 42 days post-pregnancy.

Case identification

Uses vital statistics and administrative data files data to identify and rigorously verify deaths.

Based only on death certificate data.

Relationship to pregnancy

Generated using cause-of-death and pregnancy-relatedness determinations made by expert committee review.

Maternal deaths defined only by obstetric ICD-10 codes from the death certificate data files.

* CDC's Division of Reproductive Health's Pregnancy Mortality Surveillance System (PMSS) reports the national pregnancy-related mortality ratio

** CDC's National Center for Health Statistics' National Vital Statistics System CDC's National Center for Health Statistics' National Vital Statistics System (NVSS) reports the national maternal mortality ratio

Funded by the federal Title V Maternal and Child Health Block Grant, CA-PMSS relies on a collaboration with three key partners: The Public Health Institute , Stanford University's California Maternal Quality Care Collaborative , and a volunteer review committee of experts.

Key Findings

  • California's pregnancy-related mortality ratio (PRMR) in 2019 was 12.8 deaths per 100,000 live births and was lower than the PRMR of 16.1 in 2018. California's PRMR began to rise gradually in 2013 and peaked in 2018.
  • California's PRMR was consistently lower than the U.S. PRMR from 2011 through 2017.

Pregnancy-Related Mortality Ratio in U.S. and California, 2011-2019

Line graph showing pregnancy-related mortality ratio in the U.S. and California from 2011 through 2019. Californiaā€™s pregnancy-related mortality ratio was consistently lower than the U.S. PRMR from 2011 through 2017 (the latest available data for U.S.).  In 2019, Californiaā€™s pregnancy-related mortality ratio was 12.8 deaths per 100,000 live births. It was lower than the pregnancy-related mortality ratio of 16.1 in 2018. (Of note, this was not a statistically significant decline

Pregnancy-related mortality ratio (PRMR) = Number of pregnancy-related deaths per 100,000 live births, up to one year after the end of pregnancy. Pregnancy-relatedness determinations were made through a structured expert committee case review process. Data on U.S. PRMR are published by CDC Pregnancy Mortality Surveillance System (accessed at Pregnancy Mortality Surveillance System | Maternal and Infant Health | CDC on January 19, 2022). 

  • The rate of pregnancy-related deaths from hypertensive disorders of pregnancy (preeclampsia/eclampsia) decreased significantly in 2017-2019. For the first time, hypertensive disorders are no longer among the top five leading causes of pregnancy-related deaths in California.
  • Cardiovascular disease continued to be the leading cause of pregnancy-related deaths in 2017-2019, followed by hemorrhage, sepsis or infection, thrombotic pulmonary embolism, and amniotic fluid embolism.

Pregnancy-Related Mortality Ratio by Cause in California, 2011-2019

Californiaā€™s annual pregnancy-related mortality ratios (PRMRs) remained low and largely stable in 2008-2016, except for spike in 2009

Pregnancy-related mortality ratio (PRMR) = Number of pregnancy-related deaths per 100,000 live births, up to one year after the end of pregnancy. Pregnancy-relatedness determinations were made through a structured expert committee case review process. Abbreviations: CVD = Cardiovascular disease; Hem = Hemorrhage; Sepsis = Sepsis or infection; HDP = Hypertensive disorders of pregnancy; TPE = Thrombotic pulmonary embolism; AFE = Amniotic fluid embolism. 

*Significant decline in PRMR for deaths due to hypertensive disorders of pregnancy.

  • Racial/ethnic disparities in the rates of pregnancy-related deaths narrowed in 2017-2019 but persist. The PRMR for Black birthing people was three to four times higher than the PRMRs for all other racial/ethnic groups in California. The PRMRs for Asian/Pacific Islander and Hispanic/Latina birthing people gradually increased from 2011 through 2019.

Pregnancy-Related Mortality Ratio by Race/Ethnicity in California, 2011-2019

Bar chart showing pregnancy-related mortality ratios by race-ethnicity in California across 3-year periods: 2011-2013, 2014-2016 and 2017-2019. Racial-ethnic disparities in pregnancy-related mortality ratios narrowed in 2017-2019 but persisted. Black birthing people continued to have the highest pregnancy-related mortality ratio of all racial-ethnic groups in California. In 2017-2019, the pregnancy-related mortality ratio for Black birthing people was 3 to 4 times higher than the pregnancy-related mortality ratios for Hispanic/Latinx, Asian/Pacific Islander and White birthing people ā€“ a decrease from the 4 to 6-fold difference seen in 2014-2016Pregnancy-related mortality ratio (PRMR) = Number of pregnancy-related deaths per 100,000 live births. Pregnancy-related deaths include deaths within a year of pregnancy from causes related to or aggravated by the pregnancy or its management, as determined by expert committee review. 

Methodology

Health Equity

On the Horizon

Meet the Team

CA-PMSS Project Team

CDPH MCAH Division

Paula Krakowiak, PhD, MS ā€“ Team Lead

Dan Sun, MA

Public Health Institute

Christy McCain, MPH

Delphina Alvarez

California Maternal Quality Care Collaborative

Elliott K. Main, MD

Christine H. Morton, PhD

Past team members:

David J. Reynen, DrPH, MA, MPPA, MPH, CPH

Diana E. Ramos, MD, MPH

CA-PMSS Review Committee

Elliott K. Main, MD ā€“ Committee Chair

California Maternal Quality Care Collaborative

(Maternal Fetal Medicine)

Maurice Druzin, MD

Stanford University

(Maternal Fetal Medicine)

Afshan Hameed, MD

University of California, Irvine

(Cardiology, Maternal Fetal Medicine)

Thomas Kelly, MD

University of California, San Diego

(Maternal Fetal Medicine)

Natalie Martina, CNM, MSN

Alta Bates Medical Center, Berkeley

(Nurse Midwifery)

Past committee members:

Kimberly Gregory, MD, MPH
Cedars-Sinai Medical Center
(Maternal Fetal Medicine)

Marla Seacrist, PhD, RNC
California State University, Stanislaus
(Obstetric and Neonatal Nursing)

Page Last Updated :