Pre-eclampsia and hypertension in pregnancy

High blood pressure during pregnancy

High blood pressure can develop during pregnancy and may sometimes be a sign of a condition requiring closer monitoring.

Two terms you may hear are gestational hypertension and pre-eclampsia. Although both can involve high blood pressure, they are different conditions and may require different types of monitoring and treatment.

Regular antenatal appointments are important because some women with high blood pressure or pre-eclampsia may have few or no symptoms.

What is gestational hypertension?

Gestational hypertension is high blood pressure that develops after 20 weeks of pregnancy.

It does not necessarily mean that you have pre-eclampsia. Your maternity care team may monitor your blood pressure more frequently and may arrange blood and urine tests to check whether there are any signs that other organs are being affected.

Depending on your individual circumstances, your care may also include monitoring your baby’s growth and wellbeing and medication to lower your blood pressure.

Your maternity team will discuss your individual management plan with you.

What is pre-eclampsia?

Pre-eclampsia is a pregnancy complication that usually develops after 20 weeks of pregnancy.

It involves high blood pressure and may affect other organs in your body, including the kidneys, liver, brain and blood-clotting system. Pre-eclampsia can also affect the placenta and your baby’s growth.

Some women have no obvious symptoms and are diagnosed during a routine antenatal appointment. This is why attending your regular pregnancy appointments is important.

Pre-eclampsia can also develop after your baby is born, so it is important to know the warning signs during the postnatal period as well.

What causes pre-eclampsia?

The exact cause of pre-eclampsia is not completely understood. It is thought to involve the development and function of the placenta and changes in the way the mother's blood vessels respond during pregnancy.

Pre-eclampsia can develop gradually or, in some cases, progress quickly. As it can affect several organs, your maternity team may monitor your blood pressure, urine, blood tests and your baby's growth and wellbeing.

What are the symptoms of pre-eclampsia?

Some women with pre-eclampsia have no obvious symptoms. Warning signs can include:

• A severe or persistent headache, particularly if it does not improve with simple pain relief
• Changes to your vision, such as blurred vision, flashing lights or spots
• Pain below your ribs or in the upper part of your abdomen
• Sudden swelling of your face, hands or feet
• Feeling very unwell
• Nausea or vomiting that is unusual for you
• Shortness of breath or difficulty breathing

If you experience any of these symptoms during pregnancy or after birth, contact your maternity care provider, obstetrician or hospital maternity unit promptly.

If you have severe symptoms or feel seriously unwell, seek urgent medical attention.

When to seek help

Contact your maternity team promptly if you develop a severe or persistent headache, changes to your vision, pain below your ribs, sudden swelling or feel very unwell.

Why is pre-eclampsia taken seriously?

Most women with pre-eclampsia can be safely managed with appropriate monitoring and treatment. However, pre-eclampsia can sometimes become serious or progress quickly.

Possible complications include:

• Eclampsia, which is a seizure associated with pre-eclampsia
• HELLP syndrome, a serious condition affecting the liver, blood and blood-clotting system
• Liver or kidney problems
• Stroke
• Placental abruption
• Problems with your baby's growth and wellbeing
• Premature birth

If pre-eclampsia affects the function of the placenta, your baby may not receive enough oxygen and nutrients to grow as expected. Your maternity team may therefore recommend additional monitoring of your baby's growth and wellbeing.

What puts me at greater risk of pre-eclampsia?

Some factors can increase your chance of developing pre-eclampsia. These include:

Higher-risk factors:

• Pre-eclampsia or a hypertensive disorder in a previous pregnancy
• Chronic high blood pressure
• Chronic kidney disease
• Type 1 or type 2 diabetes
• Certain autoimmune conditions
• A multiple pregnancy, such as twins or triplets

Other factors that may increase risk:

• First pregnancy
• Being 40 years of age or older
• A close family history of pre-eclampsia e.g Mother or sister
• A pregnancy interval of more than 10 years
• Higher maternal BMI
• Certain pre-existing medical conditions

Having one or more risk factors does not mean that you will develop pre-eclampsia.

Your maternity care provider will assess your individual circumstances and discuss any additional monitoring or preventative treatment that may be appropriate.

Can pre-eclampsia be prevented?

There is no way to completely prevent pre-eclampsia. For women who are at increased risk, a doctor or obstetrician may recommend low-dose aspirin during pregnancy.

The timing and dose should be based on your individual circumstances and your healthcare provider’s advice. Do not start aspirin or any other medication during pregnancy without first discussing it with your doctor, obstetrician or midwife.

Regular antenatal care is also important so that changes in your blood pressure, urine tests, blood tests and your baby's growth can be identified early.

How is pre-eclampsia treated?

Treatment depends on how severe the condition is and how many weeks pregnant you are.

Management may include:

• Regular blood pressure monitoring
• Blood and urine tests
• Medication to lower blood pressure
• Additional monitoring of your baby's growth and wellbeing
• More frequent antenatal appointments
• Hospital admission if closer monitoring or treatment is required

The only definitive cure for pre-eclampsia is the birth of the baby and placenta. However, this does not necessarily mean that your baby needs to be born immediately.

Your obstetrician and maternity team will consider your health, your baby's wellbeing, your gestation and the severity of the condition when discussing management and birth with you.

What about after my baby is born?

Pre-eclampsia can continue or develop for the first time after birth.

Your blood pressure may remain high or increase in the days following birth, so it is important to continue monitoring for symptoms and attend any follow-up appointments arranged by your maternity team.

Seek medical advice promptly if you develop:

• A severe or persistent headache
• Changes to your vision
• Pain below your ribs
• Sudden swelling
• Shortness of breath
• Feeling very unwell

Future pregnancies

Having pre-eclampsia in one pregnancy can increase your chance of developing it in a future pregnancy. If you have previously experienced pre-eclampsia or another hypertensive disorder during pregnancy, talk with your doctor or obstetrician before or early in your next pregnancy.

Your maternity care provider can review your previous pregnancy, assess your individual risk and discuss whether preventative treatment, such as low-dose aspirin, is appropriate.

Remember

If you are concerned about your health or your baby’s wellbeing, don’t wait for your next appointment. Contact your maternity team for advice.

References and further information

• Pregnancy, Birth and Baby: High blood pressure during pregnancy
• Health direct: pre-eclampsia