Australia's mothers and babies

In 2021, in Australia, 3,016 babies died in the perinatal period (from 20 weeks of gestation to 28 days after birth). Three-quarters (2,278) were stillbirths and the remaining 738 were neonatal deaths. This chapter provides information related to these deaths, including trends, an international perspective, maternal characteristics, baby characteristics, timing, causes, and investigations (autopsy and placental examination).

Overview of perinatal deaths

Australia is one of the safest places in the world for a baby to be born, yet death occurring within the perinatal period is not uncommon. On an average day in Australia, 6 babies are stillborn and 2 die within 28 days of birth (neonatal death).

In 2021, there were:

• 315,705 babies born to 311,360 women
• 3,016 perinatal deaths (1% of babies born). Of these deaths, just over three-quarters (76%) were stillbirths (2,278) and 24% (738) were neonatal deaths (Figure 1)
• 9.6 perinatal deaths per 1,000 births (7.2 stillbirths per 1,000 births and 2.4 neonatal deaths per 1,000 live births).

Figure 1: Overview of perinatal deaths in 2021

Note: Proportions for the timing of perinatal deaths (shown in the donut chart) were calculated after excluding perinatal deaths where timing is not stated or unknown and hence do not add to the totals shown at the top of the figure.

Chart: AIHW. Source: AIHW analysis of the National Perinatal Mortality Data Collection.

How have perinatal mortality rates changed over time?

Between 2003 and 2021, the rate of perinatal death varied between 9.1 and 10.5 deaths per 1,000 births, with a slight decrease from 2003 (Figure 2). The rate has decreased over this period for 2 categories in particular:

• stillbirths occurring at 28 weeks’ gestation or more
• neonatal deaths of babies born at 23 weeks’ gestation or more.

The overall stillbirth rate has remained between 6.7 and 7.7 per 1,000 births between 2003 and 2021. The rate in 2021 (7.2 per 1,000 births) is lower than in 2020 (7.7) – which marked a 20-year high-point – and the same as in 2019.

The high rate in 2020 coincided with events such as the severe bushfires and the first year of the COVID-19 pandemic in Australia. However, as the changes are similar to year-to-year fluctuations observed in the stillbirth rate since 2003, determining the impact of these events on the stillbirth rate is complex. This is partly due to the small number of stillbirths that occur in a year; small variations in the number can lead to large fluctuations in the stillbirth rate, meaning time series data are highly variable and should be interpreted with caution.

The high variability of stillbirth rates meant they were not included in AIHW’s previous work to investigate Maternal and perinatal outcomes during the 2020 and 2021 COVID-19 pandemic. The variability meant it wasn’t possible to establish a baseline annual trend for the years preceding the pandemic, to compare against the 2020 and 2021 stillbirth rates (AIHW 2024).

The rate of stillbirths occurring from 28 weeks’ gestation (third trimester) has declined over this period. Evidence indicates that these stillbirths, also known as late gestational stillbirths, are the most likely to be preventable (Flenady et al. 2016), though it’s acknowledged that not all stillbirths can be prevented.

Trends in perinatal mortality rates by gestational age are examined in greater detail below (see Gestational age trend).

Figure 2: Perinatal mortality rates in Australia 2003–2021

Notes:

1. The rate is the number of deaths per 1,000 births. Stillbirth and perinatal death rates were calculated using total births (livebirths and stillbirths). Neonatal death rates were calculated using live births.
2. Data for 2002 and 2009 were excluded from the model as data are missing from some states and territories for these years.
3. The stillbirth rate reported for stillbirths from 28 weeks’ gestation is similar to the rate reported using the WHO definition for international comparison. For more information see Perinatal mortality rates for international comparison.

Chart: AIHW. Source: AIHW analysis of the National Perinatal Mortality Data Collection and the National Perinatal Data Collection

For data on perinatal mortality rates over time see tables 1 and 5 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

An international perspective

Stillbirths

The rate of stillbirths in Australia, using the WHO definition (stillbirth born at 28 weeks’ gestation or more, or 1,000 grams birthweight or more), has decreased from 3.3 per 1,000 births in 2003 to 2.5 per 1,000 births in 2021.

For context, using the WHO definition, the estimated worldwide stillbirth rate in 2021 was 14 stillbirths per 1,000 births. This varied from 2–3 stillbirths per 1,000 births in Europe, North America, and Australia and New Zealand, to 21 stillbirths per 1,000 in sub-Saharan Africa (UNICEF 2023).

Neonatal deaths

The estimated worldwide neonatal mortality rate in 2021 was 18 neonatal deaths per 1,000 live births. This varied from 2–3 neonatal deaths per 1,000 live births in Europe, North America, and Australia and New Zealand, to 27 neonatal deaths per 1,000 live births in sub-Saharan Africa (UNICEF 2024).

The rate of neonatal deaths in Australia decreased from 3.1 per 1,000 live births in 2003 to 2.4 per 1,000 live births in 2021. The rate of neonatal deaths in Australia is the same using both the Australian and WHO definitions.

Data on perinatal mortality rates over time using the Australian and WHO definitions can be explored in the interactive data visualisation below (Figure 3), with data also presented in tables 1 and 2 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Figure 3: Perinatal mortality rates in Australia, by selected definition, 2003–2021

Maternal characteristics

Key demographics

The overall rate of perinatal mortality in Australia in 2021 was 9.6 deaths per 1,000 births. Perinatal mortality rates were higher among babies born to:

• women who accessed 2 or fewer antenatal visits (96 perinatal deaths per 1,000 births)
• women with pre-existing diabetes mellitus (27 deaths per 1,000 births)
• women who have had a previous stillbirth (23 deaths per 1,000 births).
• women who were aged under 20 or 40 and over (21 and 14 deaths per 1,000 births, respectively)
• women who lived in Very remote areas (19 deaths per 1,000 births)
• women who have had four or more previous births (17 deaths per 1,000 births)
• First Nations women (17 deaths per 1,000 births)
• women who smoked throughout pregnancy (16 deaths per 1,000 births)
• women living in the most disadvantaged areas of Australia (12 deaths per 1,000 births for quintile 1).

Detailed data on perinatal mortality rates by selected maternal characteristics can be explored in the interactive data visualisation below (Figure 4), with data also presented in Table 3 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Figure 4: Stillbirth and neonatal mortality rates by selected maternal characteristic, 2021

Perinatal mortality rates across Australia

Rates of perinatal death in 2021 varied across Australia. Rates were highest for babies born in the Northern Territory, with 21 deaths per 1,000 births, and ranged between 6.8 and 11 deaths per 1,000 births for all other states and territories. Among states and territories, rates have been highest in the Northern Territory for each of the 5 years from 2017 to 2021.

Higher rates in the Northern Territory may reflect its higher proportion of women giving birth with at least 1 of the characteristics associated with higher rates of perinatal death (for example women living in Remote and Very remote areas, First Nations women, and women who smoked throughout pregnancy) compared with other states and territories. This warrants further exploration.

Trend data on perinatal mortality rates by selected geographic area can be explored in the interactive data visualisation below (Figure 5), with data also presented in Table 3 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Figure 5: Perinatal mortality rates by selected geographic area, 2017–2021

Country of birth

There was little difference in perinatal mortality rates for babies of women born in Australia (9.4 perinatal deaths per 1,000 births) compared with babies of women born overseas (9.3 perinatal deaths per 1,000 births). However, when differentiated by the region of the mother’s country of birth, there is considerable variation in perinatal death rates for babies of women born overseas.

For example, the lowest rates of perinatal death were among babies of women whose country of birth was in:

• Northern America (5.7 perinatal deaths per 1,000 births)
• Eastern Europe (5.8 perinatal deaths per 1,000 births)
• United Kingdom, Channel Islands and the Isle of Man (6.2 perinatal deaths per 1,000 births)

By contrast, the highest rates of perinatal death were among babies of women whose country of birth was in:

• Melanesia (23 perinatal deaths per 1,000 births)
• Central and West Africa (17 perinatal deaths per 1,000 births)
• North Africa (16 perinatal deaths per 1,000 births).

For detailed data on perinatal mortality rates by mother’s country of birth, see Table 3 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Baby characteristics

Gestational age and birthweight

Poor fetal growth is associated with an increased risk of perinatal death and with fetal distress during labour, and these babies are more likely to develop long-term health conditions later in life (Alfirevic 2015).

A baby may be small due to genetic factors, or because it is the subject of a growth restriction within the uterus. A baby may also be small due to being pre-term (born early).

Expressing birthweight in relation to gestational age allows for differences in a baby’s growth status and maturity to be taken into account when examining their health outcomes at birth.

Babies are defined as being small for gestational age if their birthweight is below the 10^th percentile specific to their gestational age and sex, as determined by national percentiles. Babies are defined as large for gestational age if their birthweight is above the 90^th percentile for their gestational age and sex.

In 2021:

• 2 in 5 perinatal deaths (40%) occurred among babies born before 23 completed weeks’ gestation
• rates of perinatal death decreased rapidly with increasing gestational age and were lowest among babies born at or near term (from 36 weeks’ gestation).

The highest rates of perinatal death in 2021 were among:

• babies born at less than 23 weeks’ gestation (just over 980 deaths per 1,000 births)
• babies born with a birthweight less than 2,500 grams (just over 110 deaths per 1,000 births)
• babies who were small for gestational age (25 deaths per 1,000 births), especially for those babies whose birthweight was less than the 3rd percentile for their gestational age (57 deaths per 1,000 births)
• multiple births (35, and 80 deaths per 1,000 births, for twin and triplet or higher plurality respectively).

Plurality

Plurality refers to the number of babies resulting from a pregnancy.

In 2021, 2.7% of all births were multiple births (twins, triplets and higher pluralities such as quadruplets), with the remainder singleton births (where only one baby was born). The perinatal mortality rate for twins (35 deaths per 1,000 births) was over 4 times that of singletons (8.7 deaths per 1,000 births), and for higher multiples (triplets or higher pluralities) it was almost 10 times that of singletons (80 deaths per 1,000 births).

As plurality increased, neonatal deaths became more prominent relative to stillbirths, with 39% of perinatal deaths in twin pregnancies being neonatal deaths, compared with 23% for singleton pregnancies. This higher proportion of neonatal death primarily relates to a greater risk of pre-term birth associated with twins and higher pluralities.

Detailed data on perinatal mortality rates by birthweight, gestational age and plurality can be explored in the interactive data visualisation below (Figure 6), with data also presented in Table 4 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Figure 6: Stillbirth and neonatal mortality rates by selected baby characteristic, 2021

Gestational age trend

As described in the Overview section, the rate of perinatal death has ranged between 9.1 and 10.5 deaths per 1,000 births between 2003 and 2021. This section provides more detail on the trends that have been observed for perinatal mortality rates at different times in pregnancy.

For perinatal deaths and stillbirths, the trends before and after 28 weeks’ gestation have been in the opposite direction, with decreasing mortality rates later in pregnancy and increasing mortality rates earlier in pregnancy. The trends somewhat counteract each other meaning important changes over time are masked when only looking at mortality rates overall, particularly for stillbirths.

In the period since 2003, perinatal mortality rates have been gradually decreasing among babies born at or after 28 weeks’ gestation. By contrast, there have been slight increases in perinatal mortality rates among babies born between 20–27 weeks’ gestation.

Stillbirths occurring from 28 weeks’ gestation, the third trimester of pregnancy, are known as late gestation stillbirths. Evidence indicates that these stillbirths are the ones most likely to be preventable (Flenady et al. 2016), though it’s acknowledged that not all stillbirths can be prevented. The rate of late gestation stillbirths in Australia has decreased from 3.3 per 1,000 births in 2003 to 2.4 per 1,000 births in 2021 (a 28% decrease).

Rates of stillbirth among babies born before 28 weeks’ gestation (second trimester) have, in contrast, increased over this period, rising from just over 460 deaths per 1,000 births in 2003 to almost 540 deaths per 1,000 births in 2021 (a 17% increase). This increase could be explained by several reasons, including improvements in data quality and improvements in the detection of congenital anomalies at earlier gestations (Schindler et al. 2022; MacArthur et al. 2023), the latter of which result in earlier diagnoses and clearer indications for the offer of termination of pregnancy. Stillbirths resulting from a termination of pregnancy are included in the rates in this report.

Neonatal deaths in both the second and third trimesters of pregnancy have decreased over this period, with deaths in the third trimester (28 weeks’ gestation or more) decreasing from 1.1 per 1,000 births in 2003 to 0.8 per 1,000 births in 2021 (a 32% decrease).

Detailed data on trends in perinatal mortality rates by gestational age can be explored in the interactive data visualisation below (Figure 7), with data also presented in Table 5 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021.

Figure 7: Perinatal mortality rates in Australia, by selected definition, 2003–2021

Risk of perinatal death by gestational age

Identifying the periods in pregnancy where risk of perinatal death is greatest offers opportunities for targeted intervention and is an important part of improving outcomes for mothers and babies.

In 2021, the risk of a baby dying in the perinatal period was greatest earlier in pregnancy, before 24 weeks’ gestation (for stillbirths and neonatal death). The risk of a baby dying later in pregnancy was different for stillbirths and neonatal deaths.

• For stillbirths – the risk was lower between 24–35 weeks’ gestation, with the lowest risk at 30–31 weeks’; while the risk increased beyond 35 weeks’ gestation, it was still lower than that in the earlier gestational intervals.
• For neonatal deaths – the risk was lowest from 26–37 weeks’ gestation. Like with stillbirths, the increase in risk beyond 37 weeks’ was still lower than in the earlier gestational intervals (Figure 8).

Timing, causes and investigation of perinatal deaths

Timing of perinatal deaths

In 2021, where the timing of perinatal deaths was stated:

• The majority of stillbirths (85%) occurred before the onset of labour (antepartum). This accounted for 3 in 5 (62%) of all perinatal deaths.
• Over a quarter (27%) of perinatal deaths occurred during labour and/or birth (intrapartum death) or within the first 24 hours following birth (very early neonatal death).
• Three in 5 (60%) neonatal deaths occurred within the first 24 hours following birth (very early neonatal death) and were more common with earlier gestational age.
• Early neonatal death (1–7 days following birth) was more common among babies born 23–26 weeks (38%) and from 36 weeks’ gestation (30%).
• Late neonatal death (8–28 days following birth) was more common among babies born from 36 weeks’ gestation (42%).

Percentages are calculated after excluding records with ‘not stated’ values (331, or 11% of records). Care must therefore be taken when interpreting percentages.

Detailed data on the timing of perinatal deaths in 2021 can be explored in the interactive data visualisation below (Figure 9), with data also presented in Table 7 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Figure 9: Number of perinatal deaths by timing of death, 2021

Causes of perinatal death

Maternal and fetal causes of perinatal death (PSANZ-PDC)

In 2021:

• the most common causes of perinatal death were:
  • congenital anomaly (31%)
  • spontaneous preterm labour or rupture of membranes (<37 weeks’ gestation) (15%)
  • unexplained antepartum fetal death (11%)
• the most common causes of stillbirth were:
  • congenital anomaly (32%)
  • unexplained antepartum fetal death (15%)
  • maternal conditions (13%)
• the most common causes of neonatal death were:
  • spontaneous preterm labour or rupture of membranes (<37 weeks’ gestation) (35%)
  • congenital anomaly (30%)
  • antepartum haemorrhage (7%).

Detailed data on the causes of perinatal deaths in 2021 can be explored in the interactive data visualisation below (Figure 10), with data also presented in Table 8 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Figure 10: Number of perinatal deaths, by PSANZ-PDC and selected characteristic, 2021

In 2021, congenital anomaly was the most common cause of stillbirth (32% of stillbirths). This remained true across almost all groups of perinatal deaths, regardless of maternal or gestational age, plurality, baby’s birthweight percentile or the timing of death.

Some exceptions to this were for:

• Near or at term stillbirths. Unexplained antepartum fetal death was the most common cause of death for stillbirth occurring from 36+ weeks’ gestation (28%), followed by placental dysfunction or causative placental pathology (17%).
• Babies born to mothers aged under 20 or aged 20–24. Maternal conditions were the most common cause of stillbirth for babies born to mothers aged under 20 and aged 20–24 (47% and 28%, respectively). ‘Maternal conditions’ refers to deaths where a medical condition (for example, diabetes) or a surgical condition (for example, appendicitis) or an injury in the mother (including complications or treatment of that condition) is the cause.
• Multiple births. Complications of multiple pregnancy (including twin-to-twin transfusion syndrome and umbilical cords becoming entangled where the babies are in only one amniotic sac) was the most common cause for multiples (58% of stillbirths).

In 2021, spontaneous preterm labour or rupture of membranes (<37 weeks’ gestation) was the most common cause of neonatal death (35%). This was true for a number of groups of neonatal death, with the exception of the following groups, where it was usually the second most common cause of death:

• Neonatal deaths in babies considered small for gestational age. Congenital anomaly was the main cause of neonatal death for babies considered small birthweight for their gestational age (47%).
• Neonatal deaths in babies born at 36 weeks’ gestation or more. Congenital anomaly was the most common cause of neonatal death occurring at 36+ weeks’ gestation (47%). This was followed by hypoxic peripartum death (20%).
• Neonatal deaths in babies born to mothers aged 30–34. Congenital anomaly was the most common cause of neonatal death for babies born to mothers aged 30–34 (36%).
• Singleton births. Congenital anomaly was the most common cause of neonatal death for singletons (33%).

Causes of death in the neonatal period (PSANZ-NDC)

In 2021, the most common conditions causing neonatal death were:

• periviable infants (infants deemed too immature for resuscitation or continued life support, typically less than 24 weeks’ gestation; 38%)
• congenital anomaly (27%)
• neurological conditions (14%).

Data on the causes of neonatal deaths in 2021 can be explored in the interactive data visualisation below (Figure 11), with data also presented in Table 8 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Autopsy and placental examination following perinatal death

This chapter presents data on autopsy and placental examination, identified by PSANZ as core investigations (tests) to be undertaken following all perinatal deaths (Flenady et al. 2020).

Whether an autopsy was performed was reported for 95% of the 3,016 perinatal deaths in 2021, with the remainder unknown or not stated.

Of deaths where autopsy status was known, an autopsy was performed for:

• 41% of perinatal deaths (1,163)
• 43% of stillbirths (935)
• 33% of neonatal deaths (228).

In the majority of cases where autopsy was performed the type of autopsy (full, limited, or external examination) was unknown.

The frequency of autopsy varied depending on the cause of death. Autopsy was most commonly performed in perinatal deaths where the cause of death was classified as ‘placental dysfunction or causative placental pathology’ (72%), and performed least commonly when cause of death was ‘maternal conditions’ (7.0%).

When the underlying cause of stillbirth was unknown (‘unexplained antepartum fetal death’), autopsy was performed in half of cases (50%).

The frequency of autopsy also varied by timing of perinatal death, being most common among antepartum stillbirths (45%) and least common among early neonatal deaths (where the death occurred in 1–7 days; 26%).

Percentages reported above were calculated after excluding records with ‘not stated’ values (145, or 5% of records). Care must therefore be taken when interpreting percentages.

Data on autopsies for perinatal deaths in 2021 can be explored in the interactive data visualisation below (Figure 12), with data also presented in Table 10 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Figure 12: Proportion of perinatal deaths where tests were performed, 2021

Whether histological examination of the placenta was performed was reported for 66% of the 3,016 perinatal deaths in 2021, with the remainder unknown or not stated. Of these deaths, an examination was performed for:

• 83% of perinatal deaths (1,664)
• 82% of stillbirths (1,236)
• 86% of neonatal deaths (428).

Percentages were calculated after excluding records with ‘not stated’ values (1,011, or 34% of records). Care must therefore be taken when interpreting percentages.

Data on placental examination for perinatal deaths in 2021 can be explored in the interactive data visualisation above (Figure 12), with data also presented in Table 10 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).

Contributory factors

Whether contributory factor assessment was performed was reported for 68% of the 3,016 perinatal deaths in 2021, with the remainder unknown or not stated. Of these 2,049 deaths, an examination was performed for 1,360 or 66% of perinatal deaths (67% of stillbirths and 65% of neonatal deaths).

Contributory factors were identified in 295 of these perinatal deaths, or 22% of deaths with an assessment undertaken.

Contributory factors were judged to have likely contributed to the outcome in 157 deaths.

Data on contributory factor reviews in 2021 is shown in Figure 13, with data also presented in Table 10 of the supplementary data tables (Data tables: National Perinatal Mortality Data Collection annual update 2021).