Pre-eclampsia Pre-eclampsia, or pregnancy-induced hypertension, is a condition that affects some pregnant women usually during the second half of (from around 20 weeks) or immediately after delivery of their baby.

Women with pre-eclampsia have high blood pressure, fluid retention (oedema) and protein in the urine (proteinuria). If it's not treated, it can lead to serious complications such as convulsion (eclampsia). In the unborn baby, pre-eclampsia can cause growth problems.

Pregnant women with pre-eclampsia may not realise they have it. Pre-eclampsia is usually diagnosed during routine.

Mild pre-eclampsia can be monitored with blood pressure and urine tests at regular antenatal appointments and usually disappears soon after the birth. Severe pre-eclampsia may need to be monitored in hospital.

Who are affected? Mild pre-eclampsia affects up to 10% of first-time pregnancies. More severe pre-eclampsia affects 1-2% of pregnancies. If you have pre-eclampsia during your first pregnancy, you will be more likely to have it again in subsequent pregnancies.

Cause The cause of pre-eclampsia is not fully understood. However, it is thought that the does not develop properly because of a problem with the blood vessels supplying it.

To support the growing baby, the placenta needs a large and constant supply of blood from the mother. In pre-eclampsia, the placenta does not get enough blood. This could be because the placenta did not develop properly as it was forming during the first half of the pregnancy. Signals from damaged placenta affects the mother’s the mothers blood vessels causing high blood pressure(hypertension) and affect her kidney functions, causing leaking out of valuable protein in urine.

Who is most at risk? Some factors have been identified that could increase your chance of developing pre-eclampsia. These are listed below.

Symptoms Pregnant women with pre-eclampsia develop the following symptoms first:

You probably won't notice these symptoms, but your doctor should pick them up during your antenatal appointments.

High blood pressure affects 10-15% of all pregnant women, so this alone does not suggest pre-eclampsia. However, the presence of protein in the urine is a good indicator of the condition.

Progressive symptoms

As pre-eclampsia develops, it can cause fluid retention (oedema), which often causes sudden , ankles, face and hands.

Oedema is another common symptom of pregnancy, but it tends to be in the lower parts of the body, such as the feet and ankles. It will gradually build up during the day. If the swelling is sudden, and it particularly affects the face and hands, it could be pre-eclampsia.

As pre-eclampsia progresses, it may cause:

severe headaches

vision problems, such as blurring or seeing flashing lights

pain in the upper abdomen (just below the ribs)


excessive weight gain due to fluid retention

feeling generally unwell

If you notice any symptoms of pre-eclampsia, seek medical advice immediately.

Symptoms in the unborn baby

The main sign of pre-eclampsia in the unborn baby is slow growth. This is caused by poor blood supply through the placenta to the baby.

The growing baby receives less oxygen and fewer nutrients than it should, which can affect development. This is called intrauterine growth restriction, or intrauterine growth retardation.


Pre-eclampsia is diagnosed if both high blood pressure and protein in the urine are discovered during a routine antenatal appointment.

Blood pressure

Blood pressure is monitored throughout your pregnancy at regular antenatal screenings.

High blood pressure during pregnancy is usually defined as a systolic(the upper) reading of 140 mmHg or more, or a diastolic(the lower) reading of 90 mmHg or more. Severe hypertension is a systolic reading of 160 mmHg or more, or a diastolic reading of 110 mmHg or more.

Urine tests

A urine test is usually done at antenatal appointments If protein is present in your urine your doctor might ask to provide several samples of urine over a 24-hour period. These can be used to determine exactly how much protein is being lost through your urine.

Further tests

You will need more frequent antenatal appointments if you have either high blood pressure or protein in your urine. If symptoms are severe or get worse, you may be admitted to hospital for closer observation.


Pre-eclampsia can only be cured by delivering the baby. The mother is closely monitored and her blood pressure managed until delivery of the baby is possible.

If you have been diagnosed with pre-eclampsia, you will be referred for further tests. Depending on how severe your symptoms are, this could be another appointment with your doctor in a week’s time, a referral to a hospital within 48 hours or a referral to a hospital on the same day.

Further tests will determine the severity of the pre-eclampsia and whether a hospital stay is necessary.

Mild pre-eclampsia

Mild pre-eclampsia is monitored with frequent antenatal appointments. At these appointments:

your blood pressure will be checked for any increase (hypertension)

your urine will be tested for protein (proteinuria)

you will be asked about any other symptoms you have

Depending on your symptoms and situation, you will be asked to attend an antenatal appointment at least every three weeks if you are 24-32 weeks into your pregnancy. After 32 weeks of pregnancy, these appointments will be every two weeks.

Severe pre-eclampsia

If pre-eclampsia is severe, you may need to be admitted to hospital for closer monitoring and treatment. As pre-eclampsia tends to get worse rather than better, it is unlikely you will be able to go home until after the baby is born.


You and your unborn baby will be monitored in the following ways:

your blood pressure will be checked every 4-6 hours for any abnormal increases

urine samples will be taken at least every 24 hours to measure protein levels

you will be asked about any other symptoms you are having

your blood may be tested for the proteins aspartate aminotransferase (AST) and alanine aminotransferase (ALT), which can be a sign of liver damage if found in the blood

a blood test may be taken to provide information about the blood cells

you may have , which create an image of the baby to check blood flow through the placenta, measure the size of the baby and observe the baby’s breathing and movements

the baby's growth rate will be closely monitored to check for slow growth

the baby's heart rate may be monitored electronically in a process called cardiotocography, which can detect any distress in the baby


Bed rest and medication such as calcium channel blockers(e.g. nifedipine) can be used to lower blood pressure. This will reduce the likelihood of complications caused by high blood pressure, such as stroke.

You may also be prescribed anticonvulsant medication to prevent the convulsions (fits) of eclampsia. Injections of magnesium sulphate can halve the risk of pregnant women developing eclampsia. They can also be used to treat convulsions if they occur.

Premature birth

A baby born before the 37th week of pregnancy is and may not be fully developed. However, if the baby is seriously affected by pre-eclampsia or there is a strong risk of further complications, it may be necessary to deliver the baby prematurely, as this is the only way to cure pre-eclampsia. The baby might need to stay in a neonatal intensive care unit.


Given below are the complications that may arise if pre-eclampsia is not treated.


Eclampsia is a term that describes a type of convulsion (involuntary contraction of the muscles) that pregnant women can experience, most commonly bete

During an eclamptic convulsion, the mother’s arms, legs, neck or jaw will twitch involuntarily in repetitive, jerky movements. She may lose consciousness and may wet herself. The convulsions usually last less than a minute.

While most women make a full recovery after having eclampsia, there is a small risk of permanent disability or brain damage if the convulsions are severe. Of thoses who have eclampsia, around 1 in 50 will die from the condition. Unborn babies can suffocate during a seizure, and 1 in 14 may die.

Research has found that magnesium sulphate can halve the risk of eclampsia and reduce the risk of the mother dying. It is now widely used to treat eclampsia after it has occurred, and to treat women who may be at risk of developing eclampsia.

HELLP syndrome

HELLP syndrome is a combined liver and blood clotting disorder that can affect pregnant women. It is most likely to occur immediately after the baby is delivered, but can appear any time after 20 weeks of the pregnancy, and in rare cases before 20 weeks of the pregnancy.

The letters in the name, HELLP, stand for each part of the condition:

H is for haemolysis. This is where the red blood cells in the blood break down.

EL is for elevated liver enzymes (proteins). A high number of enzymes in the liver is a sign of liver damage.

LP is for low platelet count. Platelets are cells in the blood that help it to clot.

HELLP syndrome is potentially as dangerous as eclampsia, and it is slightly more common. The only way to treat the condition is to deliver the baby as soon as possible. Once the mother is in hospital and is receiving treatment, it is possible for her to make a full recovery. The main danger to the baby is from premature birth (being born before the 37th week of pregnancy).

Cerebral haemorrhage

Blood supply to the brain can be disturbed as a result of high blood pressure. This is known as a cerebral haemorrhage, more commonly stroke. If the brain does not get enough oxygen and nutrients from the blood, brain cells will start to die.

Organ problems

Pulmonary oedema is where fluid builds up in and around the lungs. This stops them from working properly by preventing them from absorbing oxygen.

Kidney failure is when the kidneys cannot filter waste products from the blood, causing toxins and fluids to build up in the body.

Liver failure causes disruption to the functions of the liver. The liver has many functions, including digesting proteins and fats, producing bile, and removing toxins. Any damage that disrupts these functions could be fatal.

Blood clotting disorder

The mother’s blood clotting system can break down (known medically as disseminated intravascular coagulation) and the proteins that control blood clotting become abnormally active.