High Blood Pressure

High Blood Pressure

Because blood pressure problems can affect the growth and well being of your baby, it is important that you keep a very close watch on your baby’s movements. If you have any concern in the change of the pattern of movements, any reduction in the movements that you feel, or if you are worried, then please contact your local labour ward or assessment unit to get checked out.

There are many types of high blood pressure in pregnancy and they all have different significance to both mum and baby. Our aim in this article is to help you understand some of the terminology that may be written in your handheld notes and what it means for you and your baby.



Usually high blood pressure occurs without any symptoms but the warning signs to look out for are as follows:

  • Obvious swelling, especially affecting the hands and face or upper body (especially if it has developed over just a few hours or days)
  • Persistent headache that wont go away (especially those that do not disappear with simple painkillers)
  • Nausea and/or vomiting
  • Severe pain just below the ribs in the middle of your abdomen
  • Visual problems (‘floaters’ are a common problem but look out for flashing lights or spots or difficulty focussing)

If you experience any of the above, contact your maternity team without delay.

"Essential" Hypertension

This means that you have had high blood pressure before you became pregnant. It is more common in women who have had high blood pressure in previous pregnancies, are overweight or who have many relatives with high blood pressure. If you have this, then you should have your blood pressure checked regularly throughout pregnancy (more frequently than the average pregnant woman who does not have high blood pressure).

There is a higher chance of developing a condition called Pre-Eclampsia. Essential hypertension on its own means very little for your baby, unless you develop Pre-Eclampsia later in the pregnancy which your midwife or doctor will be very carefully looking out for.


This is a condition specific to pregnancy. It is not apparent how or why it happens, but ultimately, the only cure is to deliver your baby. Pre-eclampsia may be written down in your notes as “PET” which is shorthand for Pre-Eclamptic Toxaemia.

PET often starts with a bit of high blood pressure or sometimes with some protein in your urine tests that the midwives do at each appointment. It can sometimes be easily controlled with medication so that your baby can be allowed to grow and develop more. You should expect to have very regular check ups and possibly more scans to check on you baby’s growth and well being. Usually women can be treated effectively with medication and monitoring, allowing the pregnancy to carry on until 37 weeks or more. Sometimes though, if you baby’s growth is affected, your blood pressure is very hard to control or if you are unwell, then the baby will need to be delivered sooner.

Any decision to deliver early will be made by your doctor based on all the evidence available, which will include blood pressure readings, urine tests, blood tests and scans.


Around 10% of pregnancies develop Pre-Eclampsia. Every year around 600 babies and 6 mums die due to Pre-Eclampsia. Pre-Eclampsia is more likely to occur in first pregnancies and the risk of women developing it in future pregnancies is 16%, and 25% if they suffered from severe Pre-Eclampsia. This rises to 55% if their baby was delivered before 28 weeks. Half of women with severe Pre-Eclampsia give birth pre-term. Pre-Eclampsia is responsible for 15% of all preterm births.

Statistics provided by Tommys.

HELLP Syndrome

This is a special type of Pre-Eclamptic Toxaemia (PET) that affects your blood tests. It can be quite difficult to diagnose and usually means that you will be in hospital and delivered quite quickly.

HELLP stands for Haemolysis Elevated Liver Low Platelets, or broken down:

  • Haemolysis – this means that some of your blood cells start to die and you become anaemic
  • Elevated Liver Enzymes – one of the tests done routinely for women with PET is a blood test to look at how well your liver is working. Monitoring how these rise or fall is a good indicator of how good or bad things are
  • Low Platelets – platelets are the bit in your blood which forms scabs or clots. If they are too low, you may not be able to have an epidural.


This is a rare, although serious complication of Pre-Eclamptic Toxaemia (PET). It means that you have had a fit as a result of your raised blood pressure. If it happens, it is likely to lead to a longer hospital stay. Your obstetric team will fully debrief you on what happened and give you recommendations for future pregnancies.


Whatever the cause of your high blood pressure, your medical team will be aiming to keep your blood pressure stable. This can be done with a combination of non-medical (lifestyle) changes and some medicines. All medicines given during pregnancy have been tried and tested to be safe.

The commonest medicines for treatment of high blood pressure are:

  • Methyldopa – this is a very old medicine, but is safe for you and your baby. It can cause you to feel quite tired and lethargic.
  • Labetolol – this is a type of medicine similar to a “beta-blocker”. It should be used with caution in women who have a tendency towards asthma and avoided in asthmatics because it can cause an asthma attack.
  • Nifedipine – this is a medication that can be given as a treatment for very high blood pressure to bring it under control quickly (this may give you a headache) or in a slow release version to keep it under control every day.

The commonest medicines for treatment of high blood pressure and Eclampsia are:

  • Magnesium Sulphate – often written as “MgSO4” in your notes, it is a medicine given directly into your vein to either stop a fit, or to prevent one occurring. This is only given in severe cases of Pre-Eclampsia or Eclampsia.
  • Labetolol Infusion – this is the same medication as the tablet version but it is given into a vein to give quicker and more versatile control over your blood pressure. It is a short term option and once you are over the worst problems, it will be changed back to the tablet version.
  • Hydralazine Infusion – this is a similar medicine to Nifedipine. Like the other medicines in this section, it is given into a vein and can be used in asthmatic women and also in women who have not responded to Labetolol.


Throughout your pregnancy your blood pressure will be monitored more closely than in a usual low risk pregnancy. As long as you do not develop Pre-Eclampsia and your baby is growing well, you should not require much intervention or extra scanning.

Pre-Eclampsia, however, can affect the growth of your baby and therefore the growth will be monitored more closely. You must inform your midwife or doctor if:

  • You feel that your baby has not grown much over the last couple of weeks.
  • Your baby’s movements have reduced recently (especially over the last 24 hours).
  • The pattern of your baby’s movements has changed.

If your team is concerned about the growth of your baby, they will request a scan to check on the growth, fluid and blood flow in the umbilical cord. Scans can check on the growth of a baby at one point in time. Two scans performed 2 weeks apart can check on the growth rate of your baby.

Blood Tests

If there are any concerns about you developing Pre-Eclampsia you will have some blood tests taken to see the effect that the blood pressure is having on your different organs. Usually, everything is healthy, but they are an important monitoring tool.


Most of the time it will be safe for you to wait and be allowed to go into labour on your own. This is safest for both you and your baby. Induction of labour may be required if your baby stops growing, your movements change/reduce or if your blood tests become abnormal.

Caesarean section may also be advised in certain situations. This can include a baby presenting breech (bottom first), a low placenta, need for premature delivery, a very small baby that may not tolerate labour well, if you need immediate delivery for your safety or if you have had previous caesarean sections.

Pre-eclampsia can also present postnatally on very rare occasions and not necessarily ‘cured’ by the birth of the baby. It is therefore important to report any symptoms which occur postnatally to your midwife, health visitor or GP without delay.