• In the California Pregnancy Mortality Surveillance System (CA-PMSS), a pregnancy-related death is defined as a death while pregnant or within one year of the end of pregnancy – regardless of the outcome, duration, or site of the pregnancy – from any cause related to or aggravated by the pregnancy or its management.
  

• Pregnancy-related deaths as defined in CA-PMSS do not include deaths due to injury, such as motor vehicle crashes, suicide, or homicide.
  

• CA-PMSS data are used to calculate the pregnancy-related mortality ratio (PRMR), an estimate of the number of pregnancy-related deaths (up to one year after the end of pregnancy) for every 100,000 live births.
  

• PRMR is a standard measure for reporting pregnancy-related deaths in a population. The PRMR is a more accurate measure than the maternal mortality ratio (MMR), another widely used measure. 
  

• In CA-PMSS, cases are identified by complex data linkage of vital records (i.e., death, birth, and fetal death files) and administrative data (i.e., patient discharge, emergency department, and ambulatory surgery center data). These data are then supplemented with coroner and autopsy reports and medical records to confirm pregnancy status, verify timing to death, and augment case information.
• An expert committee reviews the case information and determines the cause of death and whether the death was related to pregnancy. Causes of death are consistent with the Centers for Disease Control and Prevention’s Pregnancy Mortality Surveillance System (CDC-PMSS) maternal mortality classification scheme. The CA-PMSS committee includes experts in maternal-fetal medicine, cardiology, obstetric nursing, and midwifery.

• The pregnancy-related mortality ratio (PRMR) and the maternal mortality ratio (MMR) are both widely used measures of maternal mortality. The MMR, which is based on death certificate data alone, is the most widely used indicator of maternal deaths worldwide and remains a key indicator of the overall health of a population.
  
• The table below highlights the differences that make the PRMR more accurate than the MMR:
  

  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.

  
  

• CA-PMSS is the primary source for statewide surveillance of pregnancy-related deaths.
  
• The California Pregnancy-Associated Mortality Review (CA-PAMR) conducts targeted in-depth case reviews, using more detailed source data than CA-PMSS, to gain increased insight into possible contributing factors and opportunities for prevention.
  
• Both CA-PMSS and CA-PAMR utilize multiple data sources for case identification and rely on expert review committees to establish causes of death and relationship to pregnancy. However, compared with CA-PAMR, CA-PMSS’s review committee is smaller, has a narrower scope of expertise, and is provided with just enough information to determine the cause of death and relationship to pregnancy.
  
• CA-PMSS yields timely, highly accurate maternal mortality surveillance data via rapid but limited case reviews, though unlike CA-PAMR, CA-PMSS does not produce quality improvement-related data.
  

• MCAH does not plan to routinely release maternal mortality ratio data. CA-PMSS serves as the primary source for statewide surveillance of pregnancy-related mortality data.
• MCAH collaborates with CDPH's Vital Records and Statistics Division (VRSD), formerly the Center for Health Statistics and Informatics, to improve maternal death certificate data quality.
• Through this collaboration, VRSD has constructed errata files with corrected pregnancy status information that can be appended to previously issued death record files. The errata files can be requested directly from VRSD.
• Information on the timing to death and relationship to pregnancy from CA-PMSS is also included in this errata file to enable data users to calculate pregnancy-related mortality ratios and accurately measure maternal deaths in a population.​
  

• All CA-PMSS data and documents are considered confidential materials and are safeguarded to the greatest extent possible. All county, hospital, provider, and patient identifiers are omitted from case summaries prior to committee review.
  
• CA-PMSS data are reported in aggregate to preclude the re-identification of those who died. Person-level identifying information is not shared with outside researchers or the public.
  

• Pregnancy-related mortality is examined by various socialdemographic stratifications and within the context of social drivers of health by incorporating the California Healthy Places Index  (www.healthyplacesindex.org), a validated measure of community well-being.
  

Since 2016, CDPH has undertaken the following efforts to eliminate maternal health disparities:

1. Funding the Black Infant Health Program (BIH), an evidence-informed intervention that uses a group-based approach, in which participants get to meet, interact, and build a sisterhood with other Black women and birthing people. The model includes funding for core BIH staffing, childcare for BIH participants, door-to-door transportation for participants, and one-on-one case management-only option for participants who are unable to attend BIH group sessions, for each service area (26 across the state).
2. Funding the Perinatal Equity Initiative. CDPH funds 11 counties to implement at least two of five public health interventions through community-based organizations that have shown evidence-based (or evidence-informed) promise in reducing racial health disparities in birth outcomes among Black birthing people. The initiative also stipulates that counties maintain Community Advisory Boards to ensure implementation is community-driven and develop tailored public awareness campaigns to educate Black families about the disparities in birth outcomes.​
   
   
   

• CA-PMSS strives to release data on pregnancy-related deaths within two years of the year of death​. (Two years is the expected lag time for the release of final data files to identify deaths and complete reviews.) The latest data are published on the Pregnancy-Related Mortality Dashboard.​
  

• CDPH/MCAH’s goal is to publish CA-PMSS surveillance data annually and within two years of the year of death.​