Eclampsia
Eclampsia is a Greek word meaning 'bolt from the blue'. It describes one or more convulsions occurring during or immediately after pregnancy, as a complication of pre-eclampsia. Eclampsia has been recognised since ancient times, but it wasn't until the mid-nineteenth century that doctors began to realise that the fits were normally preceded by a collection of circulatory disturbances now known as pre-eclampsia. Confusingly, however, very few cases of pre-eclampsia culminate in eclampsia, while eclampsia can sometimes precede pre-eclampsia.

What are the signs and symptoms?
Eclamptic convulsions look no different from epileptic fits. The mother is gripped by synchronised, repetitive, jerky and sometimes quite violent movements involving muscle groups in the eyes, jaw, neck and limbs. The spasms lead to temporary loss of consciousness, stop the mother from breathing, may make her bite her tongue and sometimes cause urinary incontinence. Most convulsions last for a minute or less before stopping spontaneously. If they are continuous, without a break, the woman is said to be status eclampticus, which is extremely dangerous. Before they suffer an eclamptic convulsion, most women have signs of pre-eclampsia, most notably high blood pressure and/or protein in the urine. Often there are one or more warning symptoms – such as restlessness, shakiness, intense headache, upper abdominal pain or visual disturbances – before the fit occurs, although these are very common, non-specific symptoms which are usually perfectly benign. For some sufferers, however, eclampsia is entirely unheralded, and signs of pre-eclampsia appear afterwards.

When does it occur?
Eclampsia can occur at any stage during the second half of pregnancy – and some rare cases have been reported before 20 weeks. At the other extreme, the fits can occur as late as during labour or after delivery; one case has been reported as late as three weeks after delivery, although this is highly unusual.

What is the cause?
Several factors are probably involved, including: reduced blood flow to the brain, caused by a combination of small clots and spasm of the small arteries; swelling in the brain (cerebral oedema), possibly as a complication of excessive fluid retention; bleeding from small arteries ruptured by the intensity of the blood pressure.

What are the dangers?
Any woman with eclampsia is at risk of suffocation while the seizure is happening. Afterwards she may still be at risk, depending on the degree of brain damage that triggered the fit, and the severity of the underlying pre-eclampsia. Most women make a full recovery from eclampsia, but one in every 50 sufferers dies, and some are left with a permanent disability. Unborn babies whose mothers are affected by eclampsia are at risk of acute asphyxia (suffocation). About one in every 14 of these babies dies. It is now known that eclampsia occurring antenatally – particularly pre-term – tends to be more severe for both mothers and babies than eclampsia occurring during labour or after delivery (1).

What is the treatment?
Women who have fitted or who are thought to be at risk of having an eclamptic fit are now treated with Magnesium Sulphate. This has proved to be successful at treating women who already have had fits and preventing fits in women who may be in danger of developing eclampsia.

Can it be prevented?
In theory eclampsia can be prevented by vigilant antenatal care, including a well-timed delivery. But in practice, fits which occur without warning may be impossible to prevent. In the US, magnesium is routinely given to women with pre-eclampsia in the expectation that it prevents progression to eclampsia. However, this regime is not currently standard practice in the UK.

Who is at risk?
Eclampsia most commonly affects women in their first pregnancies, with teenagers and women with multiple pregnancies at highest risk. However, about one quarter of cases occur in second or later pregnancies – in most cases to women with no previous history of either pre-eclampsia or eclampsia.

What happens in the next pregnancy?
Because eclampsia is so rare, its recurrence rate is not known. About one sufferer in 20 will get pre-eclampsia in the next pregnancy, with the individual risk higher for those who suffered eclampsia relatively early in the pregnancy, and lower for those who had a fit at or near term.

Other than this, there is no way of predicting who is most likely to suffer a recurrence; and no specific means of prevention, although treatment with low-dose aspirin may be recommended in cases where the problem arose before 32 weeks. For optimum safety, any woman who has suffered eclampsia in one pregnancy should be considered 'at risk' in the next pregnancy. Former sufferers may like to consider pre-conception counselling with an expert to devise an appropriate antenatal care programme for the next pregnancy.

Eclampsia in the United Kingdom 2005
This recent survey carried out by the National Perinatal Epidemiology Unit under the newly established UK Obstetric Surveillance System (UKOSS) showed that the national incidence of eclampsia in the UK had significantly reduced since it was last studied in 1992.

It was shown that the incidence of eclampsia was 2.7 cases per 10 000 births. Thirty-eight percent of women had established hypertension and proteinuria in the week before their first fit. Ninety-nine percent of women were treated with magnesium sulphate. No women in the study died. Fifty-four women (26%) had recurrent fits. One hundred and nineteen women (56%) were admitted to intensive care or obstetric high dependency units for a median of 2 days (range 1–9). Twenty-two women (10%) were reported to have other severe morbidity after the eclamptic episode. Outcomes were known for 222 infants (204 singletons and 18 twins). Eight infants were stillborn and five died in the neonatal period (perinatal mortality 59/1000 births.

Driving and seizures
The Driver and Vehicle Licensing Agency gives the following advice: "Anyone who experiences a seizure during delivery or pregnancy should stop driving and notify DVLA as soon as possible. It is their legal responsibility to notify DVLA. Having done so, each case will be looked at to see if there remains a continuing liability to fits. Many in this situation are regarded as having had provoked seizures and allowed to retain their licence."