Technical notes

The National Maternal Mortality Data Collection

This report is compiled from data held in the National Maternal Mortality Data Collection (NMMDC). The NMMDC was established by the Australian Institute of Health and Welfare (AIHW) and collates data from state and territory sources on women reported to have died while pregnant or within 42 days of the end of pregnancy between 2006 and 2023.

The AIHW receives jurisdictional data only, and does not source, validate or review maternal deaths independently. The state and territory health authorities and other relevant jurisdictional bodies receive clinical data on the women who died from patient administrative and clinical records. For all jurisdictions (except the NT, where reviews are undertaken within the territory health department) the data also go to the state and territory maternal mortality committees (STMMCs), where death reviews are undertaken.

A confidential inquiry into each of the known maternal deaths that occurred in 2021–2023 was conducted by the relevant STMMC and/or health authority. 

The committees operate under legal privilege and are provided with clinical information and the results of autopsy investigations, where available. The confidential enquiry process seeks to identify and understand the individual circumstances surrounding each death. Subsequently, the STMMC agrees on the causes of each death, and assigns the death to a maternal death category. The cause of death assigned by the STMMC may subsequently be updated by the committee following receipt of a final Coroner’s report.

There is no standardised method of identifying and collecting data on maternal deaths, and no nationally agreed process of reporting or investigation. The organisational and governance arrangements – including relevant legislation, policy, and process for maternal death data collection – varies by state and territory. For example, in some jurisdictions, reporting of maternal deaths to the relevant authority is mandatory, whereas others rely on investigative efforts by state or territory health authorities. The NMMDC reflects these variations. In all cases, the best available information was used to inform the NMMDC’s investigations.

Data from the NMMDC included in this report were extracted from the collection in October 2025.

Data on the number of women giving birth were sourced from the National Perinatal Data Collection. The collection includes data on women in Australia who gave birth to at least one baby (either a live birth or a stillbirth) of at least 20 weeks’ completed gestation or at least 400 grams birthweight. Live births and stillbirths include termination of pregnancy after 20 weeks.

For more information on these collections, see:

Advisory groups

The AIHW routinely engages with the following committees regarding maternal and perinatal reporting:

Measuring maternal mortality

Maternal mortality is an internationally accepted measure of maternal health, with the following measures commonly used by United Nations agencies including WHO, UNICEF and UNFPA (WHO 2025).

The maternal mortality rate (also known as the maternal death rate) is the number of maternal deaths in a given period, per 100,000 women of reproductive age during the same period. It reflects the frequency with which women are exposed to risk of death through fertility.

The maternal mortality ratio (MMR) is the number of maternal deaths during a given period, per 100,000 women giving birth during the same period. Coincidental and deaths not yet classified are excluded from the calculation of the MMR. This is a measure of the risk of death once a woman has become pregnant. This measure is predominantly used in this report.

Although the most appropriate denominator for estimating maternal mortality would be the number of women at risk (the number of pregnant or recently pregnant women), this number is not available in Australia. This is because the number of pregnancies ending before 20 weeks’ gestation is unknown.

The denominator used for calculation of the MMR for some international reporting uses live births as the denominator for estimating maternal mortality (for example, WHO). This method allows for consistent international comparison where some countries may not have strong ascertainment of pregnancies not ending in a live birth (Studnicki et al, 2019). 

However, in Australia, accurate population data are available in the AIHW’s National Perinatal Data Collection for the number of women who gave birth to at least one baby (either a live birth or a stillbirth) of at least 20 weeks’ completed gestation or at least 400 grams birthweight. Therefore, the denominator used when calculating Australia’s MMRs in this report includes births resulting in either a live birth or a stillbirth.

MMR = (Number of direct and indirect maternal deaths(a)) / (Number of women who gave birth(a)) x 100,000

(a) For a defined place and time, resulting in either a live or stillbirth

History of reporting maternal deaths in Australia

Maternal mortality in Australia has been reported nationally since 1964. Reports were triennial until the 2003–2005 period, followed by overlapping quinquennial reports for the periods 2006–2010 and 2008–2012 (AIHW 2014, 2015). Triennial reports recommenced with the period 2012–2014 (AIHW 2017). Please see ‘Report editions’ for previous maternal deaths reports.

Maternal deaths data are also reported annually in Australia’s Mothers and Babies.

Terminology used in this report

This report uses the terms ‘woman’ and ‘women’ to mean ‘female' when referring to data collected in the National Maternal Mortality Data Collection (NMMDC) and the National Perinatal Data Collection (NPDC) as these data sources are based on sex. Information on gender is not recorded in these data collections. ‘Woman’ and ‘women’ typically refers to groups of people aged 18 years and over, however in this report people who were pregnant or gave birth aged less than 18 are included.

The terms ‘mother’ and ‘mothers’ refers to females who were pregnant and within the scope of these data collections.

It is acknowledged that this report includes people who do not identify as women or mothers, and that individual parents and families may use different words to those used in this report. This may include women, transgender men, intersex people, non-binary and gender diverse people.

Classification of psychosocial maternal deaths

In 2025, the National Maternal and Perinatal Mortality Clinical Excellence Group (NMPMCEG) reconfirmed an earlier agreement to standardise the classification of maternal deaths due to psychosocial causes (including substance use complications, homicide, and suicide). AIHW reviewed the NMMDC and identified historical maternal deaths with a psychosocial cause of death that had been classified as coincidental. As per the NMPMCEG standard, these deaths were reclassified from coincidental to indirect. As a result, there are minor differences in maternal death rates (for indirect and total) in this report compared with previous AIHW reporting.

In the NMMDC, maternal deaths by suicide are classified as direct maternal deaths where maternal mental health issues that first presented during pregnancy were identified, and as indirect maternal deaths where a mental health condition was identified before the pregnancy. This approach to classification of suicide, developed by AIHW’s NMPMCEG in 2017, differs from the WHO classification, which recommends that all deaths by suicide be classified as direct deaths (Pattinson et al. 2009).

The Australian maternity context

Maternity services in Australia are provided by 8 state and territory health departments and private providers. Each state and territory has differing care provision systems and care available to pregnant women and their babies. However, over the years, there have been a range of initiatives aimed at improving national consistency in maternity care. These include (but are not limited to):

  • A national review of maternity services in 2008 (Department of Health and Aged Care 2009), followed by the first National Maternity Services Plan in 2010 (AHMC 2011) and the more recent Woman-centred care: Strategic directions for Australian maternity servicesin 2019 (COAG Health Council 2019). The latter indicates that 3 areas inform shared decision-making between the woman and maternity service providers:
    • a woman’s preference
    • evidence as it applies to the woman
    • the context of care provision.

A requirement for women to be provided with access to evidence about their care is clear throughout that document, and one of the key outcomes quoted is reducing the incidence of maternal mortality. The AIHW is specifically referenced as one of the agencies that can help provide such evidence for women and their families.

  • The Australian Commission on Safety and Quality in Health Care’s (ACSQHC) National Safety and Quality Health Service (NSQHS) Standards (ACSQHC 2021). These standards were developed in collaboration with governments, health care providers, clinicians, patients and carers, with the aim of protecting health consumers from harm and improving the quality of health service provision. The standards are crucial in the maternity context, particularly standards for the recognition of deterioration in patients, blood management, antimicrobial practices, and the need for partnership with health consumers.

Further reading

This report, Maternal deaths in Australia 2021–2023, is part of a series. The earlier editions and any published subsequently are available in Report editions. AIHW has many other publications on the health of Mothers and babies, including the Australia’s Mothers and Babies annual report, and Stillbirths and neonatal deaths in Australia.

The following publications might also be of interest.

State and territory publications:

International publications:

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