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.
Read more about the symptoms of pre-eclampsia.
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.
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.
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.