Causes of maternal deaths 2021–2023
In this report, deaths have been categorised according to their primary cause, as assessed by the state and territory maternal mortality review committees (STMMCs), after consideration of all available information. Autopsy, coronial, and other information is often only available after the health care facility admission and discharge coding process is completed. As a result, the cause of death allocated by the STMMC, and the cause reported to the National Maternal Mortality Data Collection (NMMDC), might not be the same as the initial ICD-10 coding used by the ABS.
The first part of this chapter describes the maternal deaths occurring in the most recent triennium (2021–2023) followed by a section describing the trends observed in a range of causes of maternal death since 1973–1975.
Amniotic fluid embolism: deaths related to the effects of amniotic fluid, fetal cells or debris entering the maternal bloodstream.
Anaesthetic-related: deaths where the cause was related to anaesthesia and/or a surgical procedure.
Cancer: deaths from a disease in which abnormal cells divide uncontrollably and destroy body tissue.
Cardiovascular: deaths due to a disease process (usually pre-existing) affecting the heart and/or major blood vessels.
Ectopic pregnancy: deaths due to the development of a fertilised egg at a site other than within the uterus, most commonly in the fallopian tube.
Epilepsy: deaths due to a disturbance of brain function marked by recurrent fits and loss of consciousness.
Homicide: deaths resulting from the killing of a person by another, can generally include murder and manslaughter.
Hypertensive disorders: deaths related to the effects of pre-eclampsia and eclampsia and other disorders of high blood pressure in pregnancy.
Non-obstetric haemorrhage: deaths due to haemorrhage (bleeding from damaged blood vessels) from vessels other than those in the genital tract, most commonly haemorrhage from a ruptured blood vessel in the brain or in the abdomen (for example, the splenic artery).
Obstetric haemorrhage: deaths related to haemorrhage from the genital tract, and usually being from the placenta.
Sepsis: deaths originating from an infection.
Substance use complications: deaths resulting from the consumption of alcohol and other drugs.
Suicide: deaths caused by an action intended to deliberately end one’s own life.
Thromboembolism: deaths due to obstruction of a blood vessel (most frequently the pulmonary blood vessels) by a blood clot that has become dislodged from another site in the circulation.
Other: deaths that do not fall into any of these categories.
Unclassified: deaths that the STMMC has been unable to classify due to insufficient information being available about the cause. The absence of autopsy is a key contributor to this category.
In the triennium from 2021 to 2023, there were 59 maternal deaths. The most frequent causes of maternal death reported in Australia between 2021 and 2023 were:
- For all maternal deaths:
- non-obstetric haemorrhage (8 deaths)
- cardiovascular disease (7 deaths)
- sepsis (7 deaths)
- amniotic fluid embolism (6 deaths)
- For direct maternal deaths:
- amniotic fluid embolism (6 deaths)
- obstetric haemorrhage (4 deaths)
- sepsis (3 deaths)
- suicide (3 deaths)
- thromboembolism (3 deaths), 2 of which were due to pulmonary thromboembolism
- For indirect maternal deaths:
- cardiovascular disease (7 deaths)
- non-obstetric haemorrhage (6 deaths)
- sepsis (4 deaths)
For more specific breakdowns of cause of death see Figure 5.1, and supplementary tables 14–16 (Data tables: Maternal deaths in Australia, 2021–2023).
Figure 5.1: Causes of maternal deaths by classification of death, Australia, 2021–2023
A stacked bar chart showing the causes for direct and indirect maternal deaths. The leading cause for 2021-2023 was non-obstetric haemorrhage.
Coincidental deaths
Coincidental maternal deaths are those that occur in pregnancy or within 42 days of the end of a pregnancy from causes unrelated to the pregnancy.
Internationally, cases of coincidental (also called incidental) deaths are included in maternal mortality reporting, although only direct, indirect, and unclassified deaths are included in MMR calculations.
It is important to note that ascertainment of coincidental maternal deaths is likely to be an undercount, as reporting of these deaths is not mandated in the same way as direct and indirect deaths are in many jurisdictions.
In addition to the 59 maternal deaths reported in 2021–2023, there were 21 coincidental deaths recorded (see supplementary table 22 – Data tables: Maternal deaths in Australia, 2021–2023). The leading causes of these were:
- motor vehicle trauma (6 deaths)
- cancer (6 deaths)
- non-obstetric haemorrhage (4 deaths).
The leading causes of coincidental maternal deaths in 2021–2023 are consistent with the leading causes over the past decade (2014–2023) – see tables 1 and 2 of Data tables: National Maternal Mortality Data Collection annual update 2023.