Pre-eclampsia is an illness which occurs only during pregnancy or immediately after delivery and can affect you and your baby. It is called pre-eclampsia because in rare cases woman can go on to develop fits, known in pregnancy as eclampsia. It used to be called toxaemia, and your mother and other older relatives may have known it as this. It is quite common, affecting about one in every 10 pregnancies. You are most at risk if you are a first-time mother or pregnant for the first time by a new partner. Your risk is increased if:

• A close female blood relative has had pre-eclampsia
• You suffer from high blood pressure, diabetes, kidney disease or migraine
• You are over 35
• You are carrying more than one baby

Pre-eclampsia develops in the second half of pregnancy, usually in the last few weeks. Sometimes it starts as late as during labour or even just after the baby is born. Pre-eclampsia is caused by damage to the placenta, the special pregnancy organ which supplies the baby with food and oxygen from your blood. The damaged placenta affects you and your baby in different ways. You develop problems in your circulation, which normally show up as high blood pressure, protein in your urine and swelling. For most woman the illness remains mild. But in some cases it becomes serious and affects other parts of the body, such as the liver, brain, lungs or blood clotting system. It can get worse very quickly and be dangerous.
Your baby may grow slowly or have other problems because he or she can't get enough food or oxygen from the placenta.