During pregnancy many changes take place in the blood circulation that can lead to high blood pressure (hypertension). Pregnancy related high blood pressure occurs a little more frequently in women who are expecting for the first time.

If a woman with previously normal blood pressure develops high blood pressure (hypertension) in the second half of the pregnancy, she is said to have pregnancy-induced hypertension. A more severe form of pregnancy-induced hypertension is pre-eclampsia. In pre-eclampsia, protein can also be detected in the urine (proteinuria). Pre-eclampsia occurs in 5-10% of all pregnancies, but is more frequent in women who have a multiple pregnancy. Approximately 10 to 20% develop pre-eclampsia and it occurs at an earlier stage and more severely. Women over the age of 35 also run a slightly higher risk of developing pre-eclampsia.

In a small proportion of these women a very severe form presents, in which severe complications (such as insults comparable to epilepsy) can occur. This is called eclampsia. A special form of this severe condition is known as HELLP syndrome, and can result in organ damage. This is fortunately rare.

The actual cause of pregnancy-induced hypertension and pre-eclampsia is not known.

Although most women with high blood pressure have healthy babies, there is a greater risk of having a small baby who may need to be delivered early or who may become distressed during labour. The chances of complications also depend on the time at which the hypertension began. The later in the pregnancy, the smaller the chances of complications.

Pre-eclampsia, though, is a serious condition that greatly increases the risks to mother and baby: it can cause stroke and kidney damage in the mother and restricted growth in the baby.

Women with pregnancy-induced hypertension may well not display any symptoms. Similarly, in the early stages of pre-eclampsia there may be no symptoms. This is why it is important to attend all your antenatal visits so that blood pressure checks and urine tests (for protein) are carried out regularly.

One visible sign of pre-eclampsia is swelling of the ankles known as oedema. Bear in mind, however, that swollen hands and feet can also occur in pregnant women who don’t have high blood pressure.

Symptoms of more serious problems may develop as pre-eclampsia progresses. These include headaches, vision problems (blurred vision, seeing flashes or stars), tingling in the fingers, pain in the upper abdomen, nausea and/or vomiting, and fluid retention (oedema). If you are worried then see your doctor as soon as possible.

If high blood pressure is identified, it is important to have regular checks up. You will probably be advised to take things easy and get plenty of rest. In most cases there are no untoward consequences. In severe forms, you may be admitted to hospital to better monitor you and the pregnancy, and given drugs to reduce blood pressure. In severe cases, the only option may be to deliver the babies. The chances of complications that a premature birth can involve for the babies will have to be weighed against the need to end the pregnancy due to the mother’s condition. These are often very difficult dilemmas for all concerned.

Blood pressure will eventually return to normal after the delivery and it is unlikely that there will be long-term consequences for the mother. Complications requiring medical attention in the form of anti-hypertensive medication and/or regular checks from the doctor do occasionally occur after the birth.