Postnatal hypertension

Postnatal hypertension is the medical name for high blood pressure that continues from pregnancy until after birth. It can also be high blood pressure that happens for the first time shortly after pregnancy. If you have hypertension or are at risk of getting it, we offer specialist care to look after you and your baby during pregnancy.

If you have hypertension during your pregnancy, there is a greater risk of health problems in future pregnancies and later life. You can reduce this risk by:

If we give you medicine for high blood pressure when you leave hospital, you will need to see your GP within 2 weeks.

If you are concerned about your blood pressure or feel unwell

If your baby is less than 4 weeks old contact your community midwife

If your baby is 4 weeks old or more contact a GP

In an emergency, you can attend our maternity assessment unit at St Thomas' Hospital. Call 020 7188 1723 (open 24 hours) for advice.

Symptoms may include:

  • a severe headache
  • eyesight problems, such as blurring or flashing
  • pain just below the ribs
  • being sick (vomiting)
  • shortness of breath

Caring for yourself

There are a few things that you can do to help manage your high blood pressure. 


  • follow the plan for blood pressure checks with your midwife, health visitor and GP
  • take your medicines as advised
  • speak to a GP or blood pressure clinic if you have any questions or need more medical supplies
  • have your blood pressure and cholesterol tested at least every year at your GP surgery, even if they return to normal after this pregnancy
  • see your GP as soon as possible if you become pregnant again and tell them about all of your pregnancies
  • ask your GP about starting a low amount (dose) of aspirin (75 to 150mg every day) from 12 weeks of any future pregnancy

Hypertension in future pregnancies

If you have high blood pressure before or during pregnancy, there is a greater risk of similar complications in future pregnancies. The risk depends on how severe your problem is and how many weeks pregnant you are when the high blood pressure starts.

  • There is about a 1 in 5 chance (21%) of having high blood pressure in future pregnancies.
  • If you get high blood pressure late in pregnancy (after 37 weeks), there is about a 1 in 10 to 1 in 20 chance (between 5 to 10%) of having this again at a similar time or later in your next pregnancy. However, it is likely to be less severe than the first time.
  • If you have pre-eclampsia and your baby is born at 34 to 37 weeks, there is about a 1 in 4 chance (23%) of being affected again.
  • If you have pre-eclampsia and your baby is born at 28 to 34 weeks, there is about a 1 in 3 chance (33%) of being affected again.

Pre-eclampsia can happen at a similar time or later in the next pregnancy, and it can still be severe.

Hypertension when you are older

If you have high blood pressure in pregnancy, there is an increased risk of some health problems later in life (especially if your baby is born before 37 weeks). You may be able to reduce the risk of complications if you have regular check-ups and follow a healthy lifestyle.

Health problems linked to high blood pressure include:

  • chronic hypertension (long-term high blood pressure)
  • venous thromboembolism (blood clots that can move to the lungs)
  • heart disease (problems with your heart and blood vessels, such as palpitations, heart attacks or angina)
  • cerebrovascular disease (problems with the blood vessels in your brain, such as a stroke or mini-stroke, and dementia)
  • kidney disease (problems with your kidneys that may mean you need dialysis in future) 
  • retinal disease (problems with your eyes that can lead to poor vision or blindness)

Following a healthy lifestyle

If your blood pressure is well controlled, this will reduce your chances of complications now and in the future. Here are some useful tips.


  • eat a healthy, balanced diet
  • keep to a healthy weight
  • calculate your body mass index (BMI) to see if you are a healthy weight for your height (you can do this online or ask your midwife, GP practice nurse or GP to help)
  • try to be active every day
  • aim to do at least 150 minutes of physical activity a week, through a variety of activities
  • try to keep your blood sugar levels within your targets if you have diabetes


  • do not drink too much alcohol (less than 14 units a week is recommended)
  • do not smoke or take drugs (if you smoke, our stop smoking service can help or a GP can give you details of a local programme)

Information and support

This section explains where you can find more information and support.

Action on Pre-eclampsia

This is a charity for people affected by pre-eclampsia.

Helpline: 01386 761 848, Monday to Thursday, 8.30am to 4pm

Website: action-on-pre-eclampsia.org.uk

NHS website

NHS.uk has information on healthy eating and exercise after childbirth.

Resource number: 4285/VER2
Last reviewed: January 2024
Next review due: January 2027

A list of sources is available on request.

Contact us

For general pregnancy advice or blood test results, you can call the maternity helpline

Phone: 020 7188 1723, Monday to Friday, 10am to 6pm (except for bank holidays)

Medical help

If you are concerned about your blood pressure or feel unwell, it is important to seek professional advice as soon as possible, even if it is late at night. Our maternity assessment unit (MAU) gives urgent and emergency care for up to 6 weeks after birth.

Phone: 020 7188 1723

Address: Floor 7, North Wing, St Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH

We are open 24 hours a day, 7 days a week, including bank holidays.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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