Pre-eclampsia

Pre-eclampsia is a condition that affects some pregnant women usually during the second half of pregnancy (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.

In the unborn baby, pre-eclampsia can cause growth problems.

Pre-eclampsia rarely happens before 20th week of pregnancy. Most cases occur in the third trimester (from week 27 to the birth of the baby).

Early symptoms

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

•high blood pressure (hypertension)

•proteinuria (protein in the urine)

You probably won't notice these symptoms, but your GP or midwife 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 swelling of the feet, 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)

•vomiting

•excessive weight gain due to fluid retention

•feeling generally unwell

If you notice any symptoms of pre-eclampsia, seek medical advice immediately by calling your GP surgery or NHS Direct on 0845 4647.

Without immediate treatment, pre-eclampsia may lead to a number of serious complications, including:

•eclampsia (convulsions)

•HELLP syndrome - a combined liver and blood clotting disorder

•stroke

However, these complications are rare.

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 intra-uterine growth restriction, or intra-uterine growth retardation.

Although the exact cause of pre-eclampsia is not known, it is thought to occur when there is a problem with the placenta (the organ that links the baby’s blood supply to the mother’s).

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

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 is 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.

Treating pre-eclampsia

Treatment for pre-eclampsia focuses on lowering blood pressure and managing the other symptoms, sometimes with medication.

The only way to cure pre-eclampsia is to deliver the baby. In some cases this may mean inducing labour (starting labour artificially), although this depends on how far along the pregnancy is. Being born prematurely (before the 37th week of pregnancy) can be dangerous for the baby, but delivery may sometimes be necessary to relieve the mother's symptoms.

Although it is not possible to predict and prevent pre-eclampsia, there is some evidence to show that taking aspirin and calcium supplements early in pregnancy may help. However, you should not take any medication during pregnancy without discussing it with your GP or midwife first.

Complications

In some cases further complications can develop, such as eclampsia. This is a type of seizure that can be life-threatening for the mother and the baby. However, this is rare and less than 1% of women with pre-eclampsia develop eclampsia.

Complications of pre-eclampsia are responsible for the deaths of around six women every year in the UK. Several hundred babies also die each year following complications from severe pre-eclampsia, often as a result of premature birth. Therefore, the earlier that pre-eclampsia is diagnosed and monitored, the better the outlook for mother and baby.