Pre-eclampsia

What is pre-eclampsia?

Pre-eclampsia is thought to happen when the placenta isn't working properly. It can make you and your baby quite ill if you aren't treated for it. Pre-eclampsia occurs in the second half of your pregnancy. You're most likely to develop it in the third trimester, after you've reached 27 weeks.

Your midwife or doctor will carry out tests for the following signs of pre-eclampsia each time you have your antenatal appointment:

• high blood pressure
• protein in your urine

You won't be able to tell if you have high blood pressure or protein in your wee, but you can watch out for the following symptoms of pre-eclampsia:

• sudden, severe swelling of your face, hands or feet
• severe headaches
• problems with your vision, such as blurring or flashing before your eyes
• severe pain just below your ribs
• a general feeling of being unwell

Pre-eclampsia can range from mild to severe. Mild pre-eclampsia is quite common, affecting about one mum-to-be in 10 in her first pregnancy. If it's mild you may not know that you have it until your midwife picks up signs of it during one of your antenatal checks. Early monitoring and treatment will help to keep you and your baby well.

Severe pre-eclampsia is much less common. It affects about one mum-to-be in 200.

What causes pre-eclampsia?

We can't be sure exactly what causes pre-eclampsia. It may happen as a result of the placenta not developing properly.

If you have pre-eclampsia, the flow of blood through the placenta can be reduced. This will affect your baby, because not enough oxygen or nutrients will get through to her. Missing out on these can restrict your baby's growth.

How do I know if I'm likely to get pre-eclampsia?

Although we don't fully understand the causes of pre-eclampsia, we do know that you are more likely to develop it if:

• You are pregnant for the first time (NHS 2009).
  
  
• Your sister or your mum had pre-eclampsia.
  
  
• You have had a 10-year or longer gap between pregnancies.
  
  
• You had pre-eclampsia in a previous pregnancy. One mum in five gets it again (NHS 2009).
  
  
• You are 40 or older.
  
  
• You were obese before becoming pregnant, with a body mass index (BMI) of 30 or more.
  
  
• You are expecting twins or more.
  
  
• You already have a medical problem, such as kidney disease or high blood pressure.

If any of these apply to you, your midwife may offer you more frequent checks during your pregnancy. If you are pregnant for the first time you are offered more antenatal appointments than mums who have already had a baby.

How can I prevent pre-eclampsia starting?

Unfortunately, there is no guaranteed way to prevent pre-eclampsia. The best way of ensuring that neither you nor your baby comes to any harm is to go to all your antenatal appointments. If you have to cancel your appointment for any reason, arrange another time to see your midwife as soon as possible. Each time your midwife tests your urine for protein and measures your blood pressure, she is checking for the early signs of pre-eclampsia.

It's a good idea to get to know the symptoms of pre-eclampsia, so that you know when to seek help.

Can pre-eclampsia lead to other complications?

If pre-eclampsia goes from mild to severe, it starts to affect other systems of your body as it worsens. This means you may get more serious symptoms as the condition sets in. If your midwife and doctor don't know you have pre-eclampsia, you won't get the right care and worrying complications could develop:

Eclampsia

This is a rare but serious condition. Thankfully, eclampsia affects very few mums-to-be, only one in 2,000 (RCOG 2007). Eclampsia can develop during pregnancy, during birth or even after birth. It is possible to develop eclampsia for up to four weeks after your baby is born, especially if your pre-eclampsia was severe.

Eclampsia happens when the membranes of your brain (cerebral membranes) become irritated. It can lead to seizures or convulsions . This puts both you and your baby at great risk.

Eclampsia is a grave illness. However, if you have pre-eclampsia, it is very rare for this type of complication to become so serious that it could threaten your life.