Pre-eclampsia: signs to recognise and when to call
Pre-eclampsia is a pregnancy complication involving high blood pressure and protein in the urine. It usually develops after 20 weeks and can occasionally appear shortly after birth. Many cases are mild and discovered at routine antenatal appointments, but the condition can progress quickly in some people, which is why knowing the warning signs and acting on them without delay matters so much. This article is based on NHS guidance and covers what pre-eclampsia is, who is at higher risk, the symptoms to watch for, and how it is managed.
What is pre-eclampsia?
Pre-eclampsia is defined by a combination of raised blood pressure (hypertension) and the presence of protein in the urine (proteinuria) during pregnancy. The two together indicate that the condition is affecting the kidneys and the wider cardiovascular system. It is distinct from ordinary pregnancy-related blood pressure changes and requires proper monitoring and, in some cases, active management. Because it tends to develop gradually and mild cases often produce no noticeable symptoms, it is frequently picked up during routine antenatal checks rather than because something feels obviously wrong. This is one of the reasons those appointments, including the blood pressure reading and urine dipstick test, matter at every visit.
Who is at higher risk?
Pre-eclampsia is more common in first pregnancies, but a number of additional factors increase a person's likelihood of developing it. Understanding your own risk profile helps you and your midwife decide how closely to monitor your pregnancy. Factors associated with increased risk include:
- A first pregnancy
- A body mass index above 30 at the start of pregnancy
- High blood pressure that was already present before pregnancy
- Diabetes (type 1 or type 2) or kidney disease
- An autoimmune condition such as lupus or antiphospholipid syndrome
- Being 40 or older
- A previous pregnancy affected by pre-eclampsia
- A multiple pregnancy (twins or more)
- A gap of more than 10 years since a previous pregnancy
- Pregnancy conceived through IVF
- A close family history of pre-eclampsia
Having one or more of these factors does not mean pre-eclampsia will develop, and many people who develop it have no obvious risk factors at all. If you are considered high risk, your midwife can discuss preventive measures and arrange more frequent monitoring.
Reducing the risk: low-dose aspirin
For people assessed as high risk at the booking appointment, NHS guidance recommends taking low-dose aspirin (75 mg to 150 mg) daily from 12 weeks of pregnancy onwards. The aim is to reduce the likelihood of pre-eclampsia developing or to delay its onset. Your midwife will assess your risk factors and advise whether this applies to you. If you have any concerns about taking aspirin in pregnancy, discuss them with your midwife or doctor rather than stopping or starting on your own.
Symptoms to watch for
Because mild pre-eclampsia often produces no obvious symptoms, the routine blood pressure and urine checks at antenatal appointments are the main way it is detected at an early stage. However, more significant pre-eclampsia can cause symptoms that you may notice yourself. Contact your maternity unit straight away if you experience any of the following:
- A severe headache that does not ease with paracetamol
- Problems with your vision, including blurring, flashing lights or floaters
- Severe pain just below your ribs
- Vomiting
- Sudden significant swelling of your face, hands or feet
None of these symptoms should be waited out or attributed to ordinary pregnancy discomfort. They can indicate that pre-eclampsia is progressing, and prompt assessment by a healthcare professional is essential. Do not drive yourself to hospital if you feel unwell: call your maternity unit or, if you are unable to reach them, call 999.
How pre-eclampsia is managed
There is no way to treat pre-eclampsia other than delivering the baby and placenta, which is what resolves the condition. Until delivery is appropriate, management focuses on monitoring the pregnancy carefully and keeping blood pressure within a safe range. What this looks like in practice depends on how severe the condition is and how far along the pregnancy is.
Mild pre-eclampsia may be managed with home blood pressure monitoring and more frequent antenatal visits, allowing the pregnancy to continue under close supervision. More significant cases typically require admission to hospital so that you and your baby can be watched around the clock. Medicines to control blood pressure and, in some situations, to prevent seizures (a rare but serious complication called eclampsia) may be given. If pre-eclampsia becomes severe, or if you are at or near your due date, the clinical team may recommend induction of labour or caesarean delivery to protect both you and your baby.
HELLP syndrome
HELLP syndrome is a rare but serious complication associated with severe pre-eclampsia. The name stands for haemolysis (breakdown of red blood cells), elevated liver enzymes and low platelets. It requires urgent hospital treatment and is one of the reasons why prompt assessment of pre-eclampsia symptoms is so important. Most people with pre-eclampsia will not develop HELLP syndrome, but healthcare teams monitor for signs of it because early identification makes a significant difference to outcomes.
After the birth
For most people, blood pressure begins to settle in the days after delivery and pre-eclampsia resolves without lasting effects. Your blood pressure will be monitored closely in the postnatal period, and you may need to continue blood pressure medication for a short time after going home. Your midwife and GP will tell you what to look out for and when to seek help. In rare cases, pre-eclampsia can develop for the first time after birth, so if you experience the symptoms listed above in the weeks following delivery, contact your GP or maternity unit rather than assuming everything is fine.
Frequently asked questions
What are the warning signs of pre-eclampsia?
The symptoms that require immediate contact with your maternity unit include a severe headache that does not respond to paracetamol, problems with your vision (blurring, flashing lights or floaters), severe pain just below your ribs, vomiting, and sudden significant swelling of your face, hands or feet.
Can pre-eclampsia be prevented?
For women assessed as high risk, daily low-dose aspirin from 12 weeks onwards reduces the risk of pre-eclampsia. Your midwife will assess your risk at your booking appointment. Regular antenatal appointments allow blood pressure and urine to be monitored so that pre-eclampsia can be detected early.
What happens if I am diagnosed with pre-eclampsia?
This depends on severity. Mild cases may be monitored closely with home blood pressure checks and more frequent appointments. More severe pre-eclampsia typically requires hospital admission and monitoring. In serious cases, or if you are near or at term, early delivery may be recommended.
Is pre-eclampsia dangerous?
Mild pre-eclampsia, detected early and managed well, usually resolves after birth without lasting harm. Severe or untreated pre-eclampsia can lead to serious complications, which is why routine antenatal blood pressure and urine checks, and reporting symptoms promptly, are so important.
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