Pre-eclampsiaPre-eclampsia is a complication of pregnancy. Women with pre-eclampsia have high bloodpressure, protein in their urine, and may develop other symptoms and problems. The more severepre-eclampsia is, the greater the risk of serious complications to both mother and baby. The exactcause of pre-eclampsia is uncertain but it is thought to be due to a problem with the afterbirth(placenta). The only way to cure pre-eclampsia is by delivering (giving birth to) your baby.Medication may be advised to help prevent complications of pre-eclampsia.

What are pre-eclampsia and eclampsia?Pre-eclampsia is a condition that only occurs during pregnancy. It causes high blood pressure (hypertension)and it also causes protein to leak from your kidneys into your urine. This can be detected by testing your urine forprotein. Other symptoms may also develop (see below). Pre-eclampsia usually comes on sometime after the20th week of your pregnancy and gets better within six weeks of you giving birth. The severity can vary. Pre-eclampsia can cause complications for you as the mother, for your baby, or for both of you (see below). Themore severe the condition becomes, the greater the risk that complications will develop. Around 1 in 200 pregnantwomen in the UK develop pre-eclampsia.

Eclampsia is a type of seizure (a fit or convulsion) which is a life-threatening complication of pregnancy. Lessthan 1 in 100 women with pre-eclampsia develop eclampsia. So, most women with pre-eclampsia do notprogress to have eclampsia. However, a main aim of treatment and care of women with pre-eclampsia is toprevent eclampsia and other possible complications.

Is pre-eclampsia the same as gestational high blood pressure?No. Many pregnant women develop mild high blood pressure that is not pre-eclampsia. This is known asgestational high blood pressure or pregnancy-induced high blood pressure.

Gestational high blood pressure is new high blood pressure that comes on for the first time after the 20th week ofpregnancy. Doctors can confirm this type of high blood pressure if you do not go on to develop pre-eclampsiaduring your pregnancy and if your blood pressure has returned to normal within six weeks of you giving birth. Ifyou have gestational high blood pressure, you do not have protein in your urine when it is tested by your midwifeor doctor during your pregnancy. With pre-eclampsia, you have high blood pressure plus protein in your urine,and sometimes other symptoms and complications listed below.

Note: some women may be found to have new high blood pressure after 20 weeks of pregnancy. At first, theymay not have any protein in their urine on testing. However, they may later develop protein in their urine and so bediagnosed with pre-eclampsia. You are only said to have pregnancy-induced high blood pressure (hypertension) ifyou do not go on to develop pre-eclampsia during your pregnancy.

What causes pre-eclampsia and who gets it?The exact cause is not known. It is probably due to a problem with the afterbirth (placenta). This is the attachmentbetween your baby and your womb (uterus). It is thought that there are problems with the development of theblood vessels of the placenta in pre-eclampsia and also damage to the placenta in some way. This may affectthe transfer of oxygen and nutrients to your baby.

Pre-eclampsia can also affect various other parts of your body. It is thought that substances released from yourplacenta go around your body and can damage your blood vessels, making them become leaky.

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Any pregnant woman can develop pre-eclampsia. However, there are some women who may have an increasedrisk. Pre-eclampsia also runs in some families, so there may also be some genetic factor.

You have a moderately increased risk of developing pre-eclampsia if:

This is your first pregnancy, or it has been 10 years or more since your last pregnancy.You are aged 40 or more.You are obese (your body mass index (BMI) is 35 or over).You have a pregnancy with twins, triplets, or more.Your mother or sister has had pre-eclampsia.

You have a higher risk of developing pre-eclampsia if:

You have had high blood pressure or pre-eclampsia during a previous pregnancy.You have diabetes or chronic (persistent) kidney disease.You had high blood pressure before the pregnancy started.You have antiphospholipid syndrome. (Women with this condition have an increased risk of having amiscarriage and also of developing blood clots.)You have systemic lupus erythematosus. (This is a condition that can cause various symptoms, themost common being joint pains, skin rashes and tiredness. Problems with kidneys and other organscan occur in severe cases.)

How is pre-eclampsia diagnosed?Pre-eclampsia is present if:

your blood pressure becomes high, andyou have an abnormal amount of protein in your urine.

High blood pressure (hypertension) means that the pressure of the blood in your artery blood vessels is too high.Blood pressure is recorded as two figures. For example, 140/85 mm Hg. This is said as '140 over 85'. Bloodpressure is measured in millimetres of mercury (mm Hg). The first (or top) number is your systolic bloodpressure. This is the pressure in your arteries when your heart contracts. The second (or bottom) number is yourdiastolic blood pressure. This is the pressure in your arteries when your heart rests between each heartbeat.

Normal blood pressure is below 140/90 mm Hg. During pregnancy:

Mildly high blood pressure is blood pressure between 140/90 and 149/99 mm Hg.Moderately high blood pressure is blood pressure between 150/100 and 159/109 mm Hg.Severely high blood pressure is blood pressure of 160/110 mm Hg or higher.

Some women with pre-eclampsia develop certain symptoms (see below). These symptoms may alert them tosee their doctor or midwife who will check their blood pressure, test their urine for protein and diagnose pre-eclampsia. However, other women, especially those with mild pre-eclampsia, may not know that they have pre-eclampsia. They may not have any symptoms. This is why it is very important to have regular checks of yourblood pressure and your urine during pregnancy.

Initially, a simple test can be used to check for protein in your urine. During this test, a special stick called a urinedipstick is used. If you are found to have protein in your urine on testing with a dipstick, your doctor or midwifemay suggest that your urine be collected over a 24-hour period so that the total amount of protein in your urinecan be measured.

What are the symptoms of pre-eclampsia?The severity of pre-eclampsia is usually (but not always) related to your blood pressure level. You may have nosymptoms at first, if you only have mildly raised blood pressure and a small amount of protein in your urine.

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If pre-eclampsia becomes worse, one or more of the following symptoms may develop. See a doctor or midwifeurgently if any of these occur:

Severe headaches that do not go away.Problems with your vision, such as blurred vision, flashing lights or spots in front of your eyes.Tummy (abdominal) pain. The pain that occurs with pre-eclampsia tends to be mainly in the upper partof your abdomen, just below your ribs, especially on your right side.Vomiting later in your pregnancy (not the morning sickness of early pregnancy).Sudden swelling or puffiness of your hands, face or feet.Not being able to feel your baby move as much.Just not feeling right.

Note: swelling or puffiness of your feet, face, or hands (oedema) is common in normal pregnancy. Most womenwith this symptom do not have pre-eclampsia, but it can become worse in pre-eclampsia. Therefore, report anysudden worsening of swelling of the hands, face or feet promptly to your doctor or midwife.

Rarely, pre-eclampsia and eclampsia can both develop for the first time up to four weeks after you have givenbirth. So, you should still look out for any of the symptoms above after you give birth and report them to yourdoctor or midwife.

What are the possible complications of pre-eclampsia?Most women with pre-eclampsia do not develop serious complications. The risk of complications increases themore severe the pre-eclampsia becomes. The risk of complications is reduced if pre-eclampsia is diagnosedearly and treated.

For the motherSerious complications are uncommon but include the following:

Eclampsia (described above).Liver, kidney, and lung problems.A blood clotting disorder.Bleeding into the brain (a stroke).Severe bleeding from the afterbirth (placenta).HELLP syndrome. This occurs in about 1 in 5 women who have severe pre-eclampsia. HELLP standsfor 'haemolysis, elevated liver enzymes and low platelets', which are some of the medical features ofthis severe form of pre-eclampsia. Haemolysis means that your blood cells start to break down.Elevated liver enzymes means that your liver has become affected. Low platelets means that thenumber of platelets in your blood is low and you are at risk of serious bleeding problems, as theplatelets work to help your blood to clot.

For the babyThe poor blood supply in the placenta can reduce the amount of nutrients and oxygen reaching the growing baby.On average, babies of mothers with pre-eclampsia tend to be smaller. There is also an increased risk ofpremature birth and of stillbirth. Babies are also more likely to develop breathing problems after they are born.

What is the treatment for pre-eclampsia?If you develop pre-eclampsia, you will usually be referred urgently to see a specialist (an obstetrician) forassessment and care. You may be admitted to hospital. If you develop new high blood pressure (hypertension) ornew protein in your urine, you will also usually be referred for a specialist opinion.

Tests may be done to check on your well-being, and that of your baby; for example, blood tests to check how yourliver and kidneys are working. You may also be asked to collect your urine over a 24-hour period so that theamount of protein in your urine can be measured. A recording of your baby's heart rate may be done, as well asan ultrasound scan to see how well your baby is growing and a scan to see how well the blood is circulating fromthe afterbirth (placenta) to your baby.

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Your blood pressure will be checked regularly and your urine will usually be tested at frequent intervals for protein.You should also look out for any symptoms of pre-eclampsia and tell your midwife or doctor if you develop any ofthese.

Giving birth to your babyThe only complete cure for pre-eclampsia is to give birth to your baby. At delivery, your placenta is delivered justafter your baby is born. Therefore, what is thought to be the cause of the condition is removed. After the birth,your blood pressure and any other symptoms usually soon settle.

It is common practice to induce your labour if pre-eclampsia occurs late in your pregnancy. A Caesarean sectioncan be done if necessary. The risk to your baby is small if he or she is born just a few weeks early.

However, a difficult decision may have to be made if pre-eclampsia occurs earlier in your pregnancy. The besttime to give birth to your baby has to balance several factors which include:

The severity of your condition, and the risk of complications occurring for you.How severely your baby is affected.The chance of your baby doing well if they are born prematurely. In general, the later in your pregnancyyour baby is born, the better. However, some babies grow very poorly if the placenta does not workwell in severe pre-eclampsia. They may do much better if they are born, even if they are premature.

As a rule, if pre-eclampsia is severe then delivery sooner rather than later is best. If pre-eclampsia is not toosevere then postponing delivery until nearer the full term may be best.

Other treatmentsUntil your baby is delivered, other treatments that may be considered include:

Medication to reduce your blood pressure. This may be an option for a while if pre-eclampsia isnot too severe. If your blood pressure is reduced it may help to allow your pregnancy to progressfurther before you give birth to your baby.Steroid drugs. These may be advised to help mature your baby's lungs if doctors feel that there is achance that labour will need to be induced or that they will need to deliver your baby by Caesareansection and your baby is still premature.Magnesium sulphate. Studies have shown that if mothers with pre-eclampsia are given magnesiumsulphate, it roughly halves the risk of them developing eclampsia. Magnesium sulphate is ananticonvulsant (it helps to stop you having a seizure) and it seems to prevent eclampsia much betterthan other types of anticonvulsants. It is usually given for about 24 hours by a drip (a slow infusiondirectly into a vein) around the time of delivery.

Can pre-eclampsia be prevented?There is some evidence to suggest that regular low-dose aspirin and calcium supplements may help to preventpre-eclampsia in some women who may be at increased risk of developing it.

The National Institute for Health and Clinical Excellence (NICE) provides guidance and sets quality standards toimprove people's health in the UK. NICE has suggested that women at increased risk of developing pre-eclampsia should consider taking low-dose aspirin. If you have at least two of the moderate-risk factors for pre-eclampsia listed above, or at least one of the high-risk factors listed above, NICE suggests that you take low-dose aspirin (a 75 mg tablet every day) from 12 weeks of your pregnancy until the birth of your baby.

One study involving almost 16,000 women found that calcium supplements during pregnancy were a safe way ofreducing the risk of pre-eclampsia in women at increased risk. However, previous evidence about calciumsupplements in preventing pre-eclampsia has been conflicting and confusing. So, further research is neededregarding calcium supplements and their role in pre-eclampsia prevention, including the ideal dose of calciumsupplements to take.

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Aspirin or calcium supplements are not always standard or routine treatments for all women during pregnancy.However, one or other (or both) may be suggested by a specialist if you have a high risk of developing pre-eclampsia. You should not take either aspirin or calcium supplements unless you have been advised to do so byyour specialist. Discuss it with them first.

What is my risk of developing pre-eclampsia again in a futurepregnancy?If you had pre-eclampsia in your first pregnancy:

You have somewhere between a 1 in 2 and a 1 in 8 chance of developing gestational high bloodpressure (gestational hypertension) in a future pregnancy.You have about a 1 in 6 chance of developing pre-eclampsia in a future pregnancy.

If you had severe pre-eclampsia, HELLP syndrome or eclampsia that meant that your baby had to be deliveredbefore 34 weeks, you have about a 1 in 4 chance of developing pre-eclampsia in a future pregnancy.

If you had severe pre-eclampsia, HELLP syndrome or eclampsia that meant that your baby had to be deliveredbefore 28 weeks, you have about a 1 in 2 chance of developing pre-eclampsia in a future pregnancy.

Being obese is a risk factor for pre-eclampsia (see above). If you have had pre-eclampsia in a previouspregnancy and you are planning for another pregnancy but you are overweight or obese, you should try to loseweight before you become pregnant again. This may help to reduce your chance of developing pre-eclampsia inyour next pregnancy. See separate leaflet called Obesity and Overweight in Adults for more details.

Could pre-eclampsia have any effects on my future health?Some research has shown that women who develop pre-eclampsia may have a slightly increased risk ofdeveloping high blood pressure (hypertension) and have a higher risk of having a heart attack or stroke in thefuture. However, the overall risk of developing these problems is still low. Therefore, you may wish to look at waysin which you may be able to reduce your risk of these complications by making changes to your lifestyle. Thesecan include keeping to a healthy weight, exercising regularly, eating a healthy, balanced diet and not smoking. Seeseparate leaflet called Preventing Cardiovascular Diseases for more details.

If you have had pre-eclampsia during your pregnancy, it is important that your blood pressure be checked whenyou leave hospital after you have given birth. This will usually be done by a midwife who visits you at home. Yourblood pressure should also be checked at your 6-8-week postnatal appointment to make sure that it has returnedto normal. Your urine should be checked for protein at this time as well.

Further help & informationAction on Pre-eclampsia105 High Street, Evesham, Worcs, WR11 4EB

Tel: 020 8427 4217

Web: www.apec.org.uk

PETS - Pre-Eclampsia SocietyRhianfa, Carmel, LL54 7RL

Tel: (Helpline) 01286 882685, (Office) 01702 205088

Web: www.pre-eclampsia-society.org.uk

Further reading & referencesAntenatal care: routine care for the healthy pregnant woman; NICE Clinical Guideline (March 2008)Hypertension in pregnancy; NICE Clinical Guideline (August 2010)

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Hofmeyr GJ, Lawrie TA, Atallah AN, et al ; Calcium supplementation during pregnancy for preventing hypertensive disordersCochrane Database Syst Rev. 2010 Aug 4;8:CD001059.Hypertension in pregnancy; NICE CKS, November 2010Williams D, Craft N; Pre-eclampsia. BMJ. 2012 Jul 19;345:e4437. doi: 10.1136/bmj.e4437.Trivedi NA; A meta-analysis of low-dose aspirin for prevention of preeclampsia. J Postgrad Med. 2011 Apr-Jun;57(2):91-5.doi: 10.4103/0022-3859.81858.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medicalconditions. EMIS has used all reasonable care in compiling the information but make no warranty as to itsaccuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions.For details see our conditions.

Original Author:Dr Tim Kenny

Current Version:Dr Louise Newson

Peer Reviewer:Dr John Cox

Last Checked:20/12/2012

Document ID:4486 (v39)

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