Eclampsia is a dangerous and life-threatening complication of pregnancy that occurs when women are not adequately treated for the condition pre-eclampsia. Pre-eclampsia refers to the onset of high blood pressure and proteinuria that occurs around 20 weeks into a pregnancy. Eclampsia is essentially pre-eclampsia accompanied by a form of generalized seizure called tonic–clonic seizure.
In the UK, pre-eclampsia progresses to eclampsia in around one in 4,000 pregnancies. If eclampsia goes untreated, it is usually fatal to both the mother and the baby. If a mother develops pre-eclampsia, the only way to manage the condition is to deliver the baby. However, if the pre-eclampsia is diagnosed at a stage too early to deliver the baby, the mother and baby require careful monitoring while the baby develops and matures to a stage where delivery is safe.
Pre-eclampsia can develop in the absence of any symptoms. It is therefore essential to monitor the maternal blood pressure as a routine part of prenatal care. The blood pressure is considered abnormal if two readings of 140/90 mmHg or higher are obtained when the mother is tested at least four hours apart.
Some of the symptoms of pre-eclampsia include:
- Excess protein in the urine, referred to as proteinuria
- Visual disturbances such as blurred vision, loss of vision or sensitivity to light
- Severe headache
- Abdominal pain, usually in the upper right portion of the abdomen
- Decreased urine output
- Impaired liver function
- Difficulty breathing
- Decreased blood platelet number (thrombocytopenia)
- Nausea, vomiting
- Sudden weight gain and accumulation of fluid (edema), especially in the hands and face
Risk factors for pre-eclampsia
The factors listed below are associated with an increased risk of developing pre-eclampsia:
- First pregnancy
- Age older than 40 years
- Pre-eclampsia in a previous pregnancy
- Underlying vascular disorders such as diabetes, high blood pressure and kidney disease
- Twin or multiple pregnancy
- A family history of pre-eclampsia
If the signs of pre-eclampsia are ignored, a mother is at risk of going on to develop eclampsia. Eclampsia is diagnosed based on the development of tonic-clonic seizures or coma in a pregnant woman who has no pre-existing brain disorders. If this condition develops, delivery of the baby will be arranged regardless of how developed the pregnancy is.
A convulsion is usually preceded by a loss of vision, headaches, nausea and vomiting. The seizures generally last for less than a minute, during which jerky, repetitive movements of the arms, neck, jaw and legs are seen. Although women generally recover fully from a fit, there is a small risk that permanent brain damage or disability will occur if a fit is severe. Occasionally, the mother does not experience any convulsions but instead falls straight into a coma. On awakening from the coma, some women experience a temporary loss of vision.
Around one in fifty women who develop eclampsia die from the condition and around 1 in 14 babies die during a convulsion, due to suffocation.