Eclampsia is a serious complication of pregnancy and is characterised by convulsions. Usually eclampsia occurs after the onset of pre-eclampsia though sometimes no pre-eclamptic symptoms are recognisable. The convulsions may appear before, during or after labour, though cases of eclampsia after just 20 weeks of pregnancy have been recorded.

Signs and symptoms

The majority of cases are heralded by pregnancy-induced hypertension and proteinuria but the only true sign of eclampsia is an eclamptic convulsion, of which there are four stages. Patients with edema and oliguria may develop renal failure or pulmonary oedema.

• Premonitory stage - this stage is usually missed unless constantly monitored, the woman rolls her eyes while her facial and hand muscles twitch slightly.
• Tonic stage - soon after the premonitory stage the twitching turns into clenching. Sometimes the woman may bite her tongue as she clenches her teeth, while the arms and legs go rigid. The respiratory muscles also spasm, causing the woman to stop breathing. This stage continues for around 30 seconds.
• Clonic stage - the spasm stops but the muscles start to jerk violently. Frothy, slightly bloodied saliva appears on the lips and can sometimes be inhaled. After around two minutes the convulsions stop, leading into a coma, but some cases lead to heart failure.
• Comatose stage - the woman falls deeply unconscious, breathing noisily. This can last only a few minutes or may persist for hours.

Epidemiology

It can be fatal to both mother and fetus, with just under one in 50 women dying and one in 14 of their babies also not surviving.

Bibliography

• Mayes, M., Sweet, B. R. & Tiran, D. (1997). Mayes' Midwifery - A Textbook for Midwives 12th Edition, pp. 533–545. Baillière Tindall. ISBN 0-7020-1757-4