Australia's mothers and babies

Hypertension affecting pregnancy can be pre-existing (that is, chronic) or may arise or worsen because of the pregnancy.

Pregnancy-related types of hypertension include:

• Gestational hypertension: the onset of hypertension in pregnancy, occurring after 20 weeks’ gestation, without the maternal or fetal features of pre-eclampsia 
• Pre-eclampsia: a multi-system disorder unique to pregnancy characterised by hypertension and involvement of one or more other organ systems and/or the fetus
• Eclampsia: the onset of seizures during pregnancy or the postpartum period in a woman with hypertension 

Note that women can experience more than 1 type of hypertension. 

Hypertension is a leading cause of illness and death for mothers and babies (RANZCOG 2024). Complications of hypertension that can affect the mother include cardiac problems, cerebral injury, liver and kidney failure. Those which can affect the baby include being born pre-term, being small for gestational age and being admitted to the special care nursery (Fowosere 2024; Queensland Clinical Guidelines 2021).

The Society of Obstetric Medicine of Australia and New Zealand (SOMANZ) recommend that women should have their risk of developing pre-eclampsia assessed in their first trimester of pregnancy using personal medical history, family history and test results (SOMANZ 2023).

Note that data collection methods for hypertension vary across states and territories.

Since 2018, the proportion of women in Australia with gestational hypertension remained stable at about 3% (3.2 per 100 women in 2023); as did the proportion with pre-existing hypertension (<1 per 100 women in 2023).

Although rates for pre-eclampsia and eclampsia are low, there has been an increase in the rate of women who have had either of these conditions since 2018 (2.0 per 100 women who gave birth in 2018 compared with 2.7 in 2023)

Figure 1 presents trend data on the hypertension status of women who gave birth, by selected maternal characteristics, between 2018 and 2023. Select the ‘Current data’ button to view 2023 data.

In 2023, the highest proportions of gestational hypertension were reported for women who were born in the Philippines (4.4 per 100 women who gave birth), mothers aged 40 or more (4.6 per 100) and first-time mothers (4.1 per 100).

Pre-eclampsia & eclampsia rates were highest among:

• mothers aged under 20 and mothers aged 40 and over (3.6 and 3.9 per 100 women who gave birth, respectively)
• first-time mothers (3.9 per 100)
• First Nations mothers (3.9 per 100)
• women who were born in the Philippines (4.7 per 100).

The highest proportions of pre-existing hypertension were among mothers aged 40 and over (2.5 per 100 women who gave birth) and women with a parity of 4 or more (1.5 per 100).