Pre-eclampsia & High Blood Pressure

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.

Some women have hypertension prior to the onset of pregnancy and some develop it in pregnancy (gestational hypertension). Hypertension 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. It may be due to underlying medical condition such as diabetes or kidney disease.

If you are on blood pressure medication when you get pregnant you need to be seen early to discuss the medication (much of which is safe in pregnancy). You will need to have your blood pressure and urine 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 (about 20%). Most women with hypertension will have a happy and successful outcome to their pregnancy especially if the blood pressure is well controlled throughout.

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 (midwives test at each appointment). Once a woman has both raised blood pressure and protein in her urine PET the condition is called PET. You should expect to have very regular check-ups  (often weekly or two weekly ) and more scans to check on you baby’s growth and wellbeing. Blood tests can be done to assess how the condition is progressing.

Most women with blood pressure can be treated effectively with medication and monitoring, allowing the pregnancy to carry on until the baby is well developed (delivery is often advised by 40 weeks).

In women with PET delivery is often advised earlier (usually around 37 weeks).   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 (often around 34 weeks).

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

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.

Around 10% of pregnancies develop raised blood pressure (2-4% of pregnancies are complicated by PET). Every year in the UK around 300 babies and 3 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. Pre-Eclampsia is responsible for 15% of all preterm births.

Statistics provided by APEC.

In some women PET  can affect  multiple bodily systems (this is rare). It can be difficult to diagnose and usually means that you will be in hospital and delivered quite soon after diagnosis as it is dangerous for both you and your baby. Mild abnormalities of these test are not uncommon

HELLP stands for Haemolysis Elevated Liver Low Platelets:

• Haemolysis – this means that some of your  red blood cells start to breakdown 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.
• Low Platelets – platelets are the bit in your blood which forms scabs or clots. In HELLP syndrome they tend to fall and 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/seizure as a result of your condition. If it happens, you are likely to need urgent delivery and medication. Your obstetric team will fully debrief you on what happened and give you recommendations for future pregnancies.

An eclamptic seizure needs to be declared but should not stop you from being allowed to drive.

Whatever the cause of your high blood pressure, your medical team will be aiming to keep your blood pressure in the normal range. All medicines given during pregnancy have been tried and tested to be safe.

The commonest medicines for treatment of high blood pressure are:

• 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 because it can cause an asthma attack.
• Nifedipine – this is a medication that dilates (opens up) the blood vessels. It can cause headaches in the first few days after starting (or increasing the dose).
• 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.

The commonest medicines for treatment of  severe 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.

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.

There is a relatively new blood test called PlGF (placental growth factor) which can determine if your raised blood pressure or the protein in your urine is due to PET. If this test is abnormal it is likely that you will need delivery within 2 weeks. This test is usually done between 28 and 37 weeks gestation in women with hypertension and/or proteinuria.

Women with raised blood pressure may be offered delivery any time from 38 weeks gestation (normally babies deliver at 37-42 weeks). If you have PET you will probably be offered delivery at 37 weeks (or earlier if there are concerns about you or your baby).

Labour and vaginal delivery is usually safe for you and your baby though you may need to have an induction of labour.

Caesarean section may be advised in certain situations. This can include a baby presenting breech (bottom first), a low placenta, 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.

In most women PET improves with delivery though this can take some weeks.

In most women the raised blood pressure associated with pregnancy goes back to normal within 6 weeks. In some it may remain raised for some months. You may be offered blood pressure medication, if so it will be safe in breast feeding.

Women who have had raised blood pressure in pregnancy are at risk of raised blood pressure in future pregnancies (about 20-50% risk depending on the severity). They are also more likely to develop raised blood pressure as they get older (about a doubling of the background risk).

If you are on blood pressure medication prior to pregnancy it is helpful to discuss with your doctor as some treatments should be changed before getting pregnant.

APEC – Action on Pre-Eclampsia