What is Preeclampsia?

Preeclampsia is a pregnancy disorder that affects 5% of pregnant women around the world and can turn an otherwise healthy pregnancy into a challenging and complex experience. It is a condition that can develop suddenly, often without warning. For many families, it leads to early birth and ongoing health challenges for both mother and baby. With the right information, awareness and support, women can feel less alone and better empowered to seek care and understanding during and after their pregnancy journey.

High Blood Pressure in Pregnancy

Blood pressure is a measure of how strongly blood flows through blood vessels each time the heart beats and rests. Normal blood pressure is around 90-120/60-80 mmHg.

What do the numbers mean?

  • Top number (systolic): pressure when the heart pumps
  • Bottom number (diastolic): pressure when the heart rests between beats.
In pregnancy, a blood pressure persistently greater than or equal to 140/90 mmHg is classified as high (hypertension). Increases in both the top and bottom blood pressure numbers can be linked to health problems for both the mother and the baby, so both numbers matter.

There are different classifications of hypertension in pregnancy, with the main ones being:

  • Chronic hypertension - high blood pressure that is present before pregnancy, develops early in pregnancy, or continues after birth. It may have no clear cause or be linked to another health condition (e.g. heart or kidney problem) and requires ongoing medical care and monitoring
  • White coat hypertension - high blood pressure in a clinic/hospital but normal at home. Some women with white coat hypertension in early pregnancy may later develop ongoing high blood pressure including preeclampsia, so monitoring is important
  • Gestational hypertension - high blood pressure that develops after 20 weeks of pregnancy and usually returns to normal after birth. Some women may later develop preeclampsia, so careful monitoring is important during pregnancy and after the birth
  • Preeclampsia - a serious pregnancy disorder that usually develops after 20 weeks of pregnancy. It involves high blood pressure and signs that organs such as the kidneys, liver, brain, blood, and/or the placenta are being affected. With appropriate care, blood pressure and other symptoms generally return to normal within three months after birth
  • Superimposed preeclampsia - occurs when preeclampsia develops in a woman who already has high blood pressure (chronic hypertension). It usually appears after 20 weeks of pregnancy and requires close monitoring for changes in both the mother and baby

Preeclampsia

Preeclampsia is a condition in pregnancy where high blood pressure develops after 20 weeks, along with signs that one or more body systems are affected. It is diagnosed using physical examination, urine and blood tests, and ultrasound. Signs can include:

  • Kidneys
    • Protein in the urine
    • Raised blood tests showing reduced kidney function
  • Liver
    • Raised liver enzymes
    • Pain under the right ribs
    • Vomiting
  • Brain/Nervous system
    • Severe headache
    • Visual changes (like blurred vision or flashing lights)
    • Seizures (eclampsia)
  • Blood
    • Low platelets
    • Signs of blood cell breakdown
    • Rare clotting problems
  • Placenta/baby
    • Slow fetal growth
    • Reduced amniotic fluid
    • Abnormal blood flow to the baby

When you should seek Medical Help

Some women may not notice any symptoms, which is why regular check-ups throughout pregnancy are important. However, signs and symptoms that need urgent attention can include:

  • Persistent headaches
  • Changes in vision (blurred vision, flashing lights, or sensitivity to light)
  • Sudden swelling of the face, hands, or around the eyes
  • Sudden weight gain over a short period
  • Pain under the right ribs
  • Nausea or vomiting later in pregnancy
  • Shortness of breath or difficulty breathing
  • Feeling generally unwell or “not right”
Women should seek medical advice promptly if they notice any of these symptoms, or if they have concerns about how they are feeling.

Cause of Preeclampsia

The exact cause of preeclampsia is complex and not fully understood. It is thought to begin in the placenta very early in the pregnancy, where the blood vessels do not develop or function as they should. This can stress the placenta and reduce blood flow between the mother and baby, which may trigger changes in the mother’s blood vessels, blood pressure and other body systems.

Short Term Impacts of Preeclampsia

For the Mother

  • Increased medical monitoring
  • More frequent appointments and tests
  • Higher likelihood of hospital admission and longer stays
  • Increased medical intervention such as induction of labour and caesarean section
  • Preterm birth
  • Possible admission to acute care setting

For the Baby

  • Increased monitoring before birth
  • Greater risk of preterm birth
  • Lower birth weight
  • Increased need for specialised care after birth
  • Possible admission to neonatal intensive care

Treatment of Preeclampsia

Treatment of preeclampsia focuses on keeping both mother and baby safe. This usually involves close monitoring of blood pressure and symptoms, regular blood, urine and ultrasound tests, and medications to control blood pressure. In some cases, hospital admission may be needed. The only cure for preeclampsia is delivery of the baby and placenta, so the timing of birth is carefully planned to balance the health of the mother with the baby’s maturity.

Prediction of Preeclampsia

There is no single test that can predict preeclampsia on its own. Instead, healthcare providers use a combination of information, including a woman’s medical and pregnancy history, regular blood pressure checks, blood tests, urine tests, and ultrasound assessments. In some cases, blood tests such as the sFlt-1/PlGF ratio may be used. This blood test helps doctors assess the risk of developing preeclampsia. It measures two substances related to placental function and can help predict or rule out preeclampsia in women who show symptoms. The test is sometimes offered to help guide monitoring and decisions about care.

Next Pregnancy

Most women who have had preeclampsia go on to have healthy pregnancies in the future. However, having preeclampsia does increase the chance of it happening again. It is a good idea to consult a health professional for advice when you are thinking about another pregnancy, before you are pregnant.

In a future pregnancy, women are usually offered:

  • Early and regular antenatal care
  • Thorough history taking and risk assessment
  • Closer monitoring of blood pressure and symptoms
  • Additional tests or ultrasounds as needed
  • Preventive strategies, such as low-dose aspirin, calcium and regular exercise have been shown to provide some benefit in reducing the chance of developing preeclampsia.
Speak to your health care provider and ask if these strategies are suitable for you. Early planning and ongoing care can help reduce risks and support a healthy pregnancy.

View the SOMANZ Information on Aspirin and Exercise in pregnancy.

Long Term Impacts of Preeclampsia

For the Mother

  • Greater chance of preeclampsia in future pregnancies
  • Increased risk of high blood pressure later in life
  • Increased risk of heart disease and stroke
  • Increased risk of Type 2 diabetes
  • Increased risk of kidney disease

For the Baby

  • Increased risk of high blood pressure later in life
  • Increased risk of heart and metabolic conditions
  • Possible long-term impacts related to preterm birth or low birth weight

Looking after yourself after Preeclampsia

After a pregnancy affected by preeclampsia, looking after your long-term health is important.

  • Attend annual health checks with your GP, including blood pressure monitoring and blood tests for cholesterol, lipids and blood sugar level
  • Tell your GP and other healthcare providers that you have had preeclampsia
  • Maintain a healthy lifestyle, including balanced nutrition and regular physical activity
  • Manage stress and prioritise rest and recovery
  • Seek support for emotional and mental wellbeing, as recovery can take time
  • Ask about heart and kidney health screening if recommended
Ongoing care and awareness can help reduce future health risks and support long-term wellbeing.

View the SOMANZ Infographic on Life after Preeclampsia.

View the Heart Foundation information on Long Term Health.