Pre-Eclampsia 

Evidence

Reviewing Accuracy of First Trimester Screening for Preeclampsia Using Maternal Factors and Biomarkers - PubMed (nih.gov)

Pre-eclampsia: pathophysiology and clinical implications (bmj.com)

Placental growth factor testing to assess women with suspected pre-eclampsia: a multicentre, pragmatic, stepped-wedge cluster-randomised controlled trial - PMC (nih.gov)

Education

What is Pre-Eclampsia?

Pre-eclampsia is a serious condition specific to pregnancy and typically develops after the 20th week. It can affect between 2-8% of pregnancies. Traditionally, Pre-eclampsia was diagnosed with new onset  high blood pressure (hypertension) and high levels of protein in the urine (proteinuria). The definition of pre-eclampsia has expanded over time and now also includes signs of dysfunction of the kidneys, liver or blood system. Having a small baby that may not be fulfilling it’s growth potential in the womb can also be commonly associated with pre-eclampsia, particularly when the condition is diagnosed earlier in the pregnancy.

As well as affecting your health, pre-eclampsia, particularly when it is early onset, can have a significant effect on your unborn baby. A weakened blood supply to the placenta causes a restriction in the supply of oxygen and nutrients that your baby receives, this may cause restricted fetal growth and possible lack of oxygen. Ultrasounds can check for this. Depending on the stage of pregnancy you are at, you a CTG may be used to check baby’s wellbeing. 

Pre-eclampsia can be unpredictable. In severe cases, seizures can occur and this is called eclampsia. If left untreated or unmonitored, blood pressure can get high enough to cause a stroke which can cause lasting neurological symptoms such as weakness or difficulty speaking.

There are two types of pre-eclampsia, early onset, which is identified earlier in the pregnancy (at less than 34 weeks of pregnancy) and late onset (at 34 weeks or more of the pregnancy). 

Blood pressure is the force that pushes against your blood vessel walls each time your heart squeezes and relaxes to pump the blood through your body. A blood pressure measurement is usually recorded as two numbers, such as 120 over 80 (120/80). High blood pressure is also called hypertension. Hypertension is diagnosed when either the top or the bottom number is higher than normal.

Proteinuria is a high level of protein in your urine. This condition can be a sign of kidney damage. Proteins have many important functions, including Building muscles and bones, regulating the amount of fluid in your blood, fighting off infections and repairing damaged tissues.

Am I at increased risk for pre-eclampsia?

Pre-eclampsia can occur in any pregnancy. About 3–4% of all pregnant women in Australia and New Zealand develop preeclampsia. You are more likely to develop pre-eclampsia if you:

• Are known to have high blood pressure outside of pregnancy.
• Had pre-eclampsia in a previous pregnancy.
• Have other medical problems, such as kidney disease, diabetes or an autoimmune disease.

If you have combination of the risk factors below then you also may be at a higher risk:

• Are having your first baby.
• Are aged 40 years or more.
• Have a multiple pregnancy.
• Have a family history of pre-eclampsia (for example your mother or sister had pre-eclampsia).
• Are overweight at the beginning of pregnancy (BMI 35 or more).
• Have had a gap of 10 years or more since your last pregnancy.
• Conceived with in vitro fertilisation (IVF).

Identifying risk factors alone is not a perfect way of determining women who may be at risk of pre-eclampsia. More recently there have been advances in finding out who is at increased risk. This involves adding results of additional blood tests (called PAPP-A and PlGF), a blood pressure result and ultrasound measurement of blood flow to the uterus (called a uterine artery Pulsatility Index). This is not offered at present for everybody. 

Knowing if you may be at increased risk of pre-eclampsia can be helpful as there is evidence that starting a low dose Aspirin tablet daily during pregnancy can reduce the chance or delay the onset of getting pre-eclampsia. In women with low calcium in their diets, taking calcium supplements also may reduce the risk. This preventative approach is most effective at preventing the early onset type of pre-eclampsia.

If you are at a higher risk of developing pre-eclampsia, you should be seen more frequently than if the pregnancy were low risk. It does not mean you will definitely develop pre-eclampsia. Ultrasound may also be used to assess the size of the baby and it’s wellbeing. 

What are the signs and symptoms of pre-eclampsia?

Many women with pre-eclampsia do not have any symptoms. Pre-eclampsia is often diagnosed during routine prenatal appointments when your healthcare provider checks your blood pressure.

However, women with severe pre-eclampsia will have high blood pressure and may experience:

• Sudden swelling of the face, hands or feet.
• Headache that doesn’t go away with simple painkillers.
• Problems with vision, such as blurring, flashes of light and dots before the eyes.
• Severe pain just below the ribs.
• Heartburn that doesn’t go away with antacids.
• Generally feeling very unwell.

It is very important that you contact your doctor, midwife or maternity hospital if you experience any of these symptoms.

How is pre-eclampsia diagnosed and treated?

If Pre-eclampsia is suspected, your healthcare provider may:

• Perform blood tests to check kidney, liver function and the blood clotting system.
• Obtain a urine sample to assess if there are excessive proteins in it.
• Check the baby’s heartrate, this may include a CTG depending how far in the pregnancy you are.
• Arrange an ultrasound to assess size of the baby and it’s wellbeing.
• Some providers may offer blood test measuring growth factors from the placenta (PlGF). Normal levels mean it is very unlikely you have pre-eclampsia. These tests are not available in all locations within Australia and not having access to this test does not mean that pre-eclampsia cannot be effectively diagnosed.

If pre-eclampsia is diagnosed, you may be admitted to hospital for close observation. You may be discharged and managed very closely as an outpatient in certain circumstances if appropriate.

High blood pressure can usually be controlled with medication. In more serious cases, a medication called magnesium sulphate is also given through a drip to reduce the chance of having an eclamptic seizure. Steroid injections may be given if it is thought your baby may be born early. Steroids can improve outcomes for babies born prematurely. The only complete cure for pre-eclampsia is the birth of your baby. The management of pre-eclampsia therefore depends on how far along you are in pregnancy and how seriously you and your baby are affected by the condition. In general, pregnancy is prolonged until about 37 weeks’ gestation but if there are concerns about either mum or baby’s health then birth may be advised at an earlier stage of pregnancy. Pre-eclampsia itself does not mean you necessarily need to have a caesarean section. Having a significantly preterm or small baby however may increase the chance of this being advised.

Empowerment

As the symptoms of PE may not be obvious, it is important to attend all your antenatal appointments to pick up any early signs of the condition. Ensuring that your doctor has your complete medical history and any information from other family members (mother, sister) is important as you may be at high risk of PE due to your family history.

Once diagnosed, you can take comfort in the fact that you and your baby will be well monitored, and a treatment plan will be formulated based on the severity of the condition as well as your baby’s gestation. Your doctor may refer you to a maternal fetal specialist who may be at another hospital, especially if you are at an early gestation and there is the possibility that your baby will be delivered preterm and may need the resources of neonatal doctors for the baby. It may now be the time to consider the likelihood of experiencing a premature birth and to ask any questions about what to expect.

Most mothers who have experienced PE in their first pregnancy will go on to have a normal pregnancy next time. However, there is still a small chance that your condition will reoccur which is why it is important to be closely monitored in subsequent pregnancies. Your doctor may suggest you take a small dose of aspirin to help prevent or delay symptoms of pre-eclampsia if you are deemed at risk. Generally, if PE does reoccur in subsequent pregnancies, it is less severe and appears at a later gestation.

There is growing evidence that having had pre-eclampsia in pregnancy increases the risk of developing problems with blood pressure and cardiovascular disease later in life. There are no specific recommendations as to the best way to monitor for this. It would seem sensible to make sure you have a healthy diet and lifestyle and see your GP for regular check-ups.

Feeling fully informed and knowing what to expect may make you feel prepared. Connecting with others who experienced what you are going through can be of great comfort and sharing stories may be of support.

Useful Links

The Australian Action on Pre-eclampsia Inc

 www.aapec.org.au

Pre-eclampsia Foundation

www.preeclampsia.org

COPE – Centre for Perinatal Excellence

https://www.cope.org.au/getting-help/e-cope-directory/

Panda - Perinatal Mental Health

https://panda.org.au/