Pre-eclampsia: Symptoms, Causes, Treatments & Prevention

Dr Chrissie Yu

September 2021

About 1 in 10 women suffer from high blood pressure in pregnancy. This is known as hypertension or pre-eclampsia. Most women don’t develop pre-eclampsia or experience any problems if their blood pressure is well-controlled.

Dr Chrissie Yu, Consultant Obstetrician and Fetal Medicine Specialist at the Portland Hospital, answers some of your questions about pre-eclampsia.

However, if you have any questions or concerns, please speak to your midwife or doctor.

What are the risks of high blood pressure when I’m pregnant?

Risks to mother
  • Damage to kidneys and liver.
  • Blood clotting problems.
  • Bleeding from the placenta.
  • Having a stroke and fits (seizures).
Risks to baby
  • Poor growth.
  • Premature birth.
  • Stillbirth (rare).

Are there different types of high blood pressure in pregnancy?

1. Pre-existing high blood pressure or chronic hypertension

This is high blood pressure before pregnancy. If you’re already on treatment for this it’s very important to see a healthcare professional if you are trying to conceive or you’ve become pregnant as your medication may need to change.

If you’ve high blood pressure before you’re 20 weeks pregnant, it usually means you’ve had undetected high blood pressure.

You may be given low-dose Aspirin from week 12 of your pregnancy until baby’s birth to reduce the risk of developing pre-eclampsia.

2. Pre-eclampsia

Pre-eclampsia affects 2-5% of pregnant women. It’s defined as new onset raised blood pressure (usually after 20 week’s pregnancy) with protein in the urine. It can also affect your kidneys, liver, brain and blood clotting system.

3. Eclampsia

Eclampsia (seizures or convulsions) is a rare but serious complication of pre-eclampsia. By detecting and treating pre-eclampsia, eclampsia can be prevented from developing.

4. Pregnancy-induced hypertension

This is new onset raised blood pressure after 20 week’s pregnancy without protein in the urine or organ damage. Regular blood pressure and urine checks are important as there are risks of developing pre-eclampsia later in pregnancy.

What are the symptoms of high blood pressure in pregnancy?

Many women with high blood pressure during their pregnancy experience no symptoms. It’s important to check your blood pressure and urine regularly throughout your pregnancy.

Symptoms of pre-eclampsia include:

  • Severe ongoing headaches.
  • Blurred vision, flashing lights or spots in front of your eyes.
  • Tummy pain; especially in the right upper part of the abdomen.
  • Vomiting later in pregnancy (not morning sickness of early pregnancy).
  • Sudden swelling of your hands, face or feet.
  • Feeling breathless.
  • Feeling your baby move less often.

If you’re pregnant and have any of these symptoms, please see your doctor or midwife urgently so they can check your blood pressure and test your urine.

Can pre-eclampsia be prevented?

Women at risk of developing pre-eclampsia should take low-dose Aspirin (75-150 mg) every day from 12 weeks’ pregnancy until baby’s birth. Taking low-dose Asprin before 16 weeks’ pregnancy reduces the risk of pre-eclampsia that requires premature birth.

What happens if my blood pressure is high and I’m pregnant?

Regular checks of your blood pressure, your urine, blood tests and an ultrasound scan to look at how your baby is growing may be all you need.

If your blood pressure is high, you’ll be referred to a doctor and you may require hospital admission to check the well-being of you and your baby.

As always, if you have any questions or concerns about your pregnancy, please speak to your midwife or doctor.

Can lifestyle changes reduce high blood pressure?

Some physical activity daily, such as walking or swimming, can keep your blood pressure in the normal range. Eating a balanced diet and with a low salt intake can reduce your blood pressure.

Will my labour and delivery be affected?

Sometimes, your blood pressure may worsen, or your baby’s growth may be affected, as the pregnancy continues. Induction of labour or delivery by C-section may be recommended. This may be fine if your pregnancy is near full term. However, it’s more difficult if the condition becomes severe earlier in pregnancy.

Will I get better after pregnancy?

Pre-eclampsia usually improves within six weeks of giving birth. A plan will be made for blood pressure monitoring and a postnatal review with your GP at 6 weeks. If you’ve been on medication to lower blood pressure, your GP will discuss reducing or stopping your medication.

Can I breastfeed while taking blood pressure medication?

Blood pressure medication is safe for breastfeeding.
Most medicines are not tested in pregnant or breastfeeding women, so disclaimers in the manufacturer’s information are not because of any specific safety concerns or evidence of harm.

Are there any implications for my future health?

If you had high blood pressure in pregnancy, you have an increased risk of having certain health problems later in life, such as chronic hypertension (long-term high blood pressure, cardiovascular disease (problems with your heart and your blood vessels), stroke, and kidney problems.

What can I do to help myself?

You may be able to reduce the risk of these conditions if you have regular check-ups and make healthy lifestyle choices.

  • have a yearly blood pressure measurement at your GP’s practice, even if it returns to normal after this pregnancy
  • stay healthy:
    • avoiding smoking
    • take plenty of exercise
    • have a healthy diet
    • keep your BMI within a normal range (18.5–24.9 kg/m2)

Is there anything I can do to prepare before I become pregnant again?

If you had high blood pressure late in your pregnancy (after 37 weeks), there is about a one in ten chance that it will happen again at a similar time or later in your next pregnancy but it is likely to be less severe than the first time.
If you had high blood pressure early and/or had severe effect on your pregnancy (delivery before 34 weeks, or you had a very small baby), there is about a four in ten chance that you would be affected again. The effect tends to occur later in the next pregnancy, but it can still be severe.
If you get pregnant again, please make sure you see your GP as soon as possible and ask about starting low-dose aspirin (75-150mg daily) from 12 weeks’ gestation to reduce the risk of pregnancy complications