Eclampsia is the occurrence of one or more seizures in a person with a hypertensive pregnancy disorder, particularly Pre-eclampsia, when the seizures cannot be better explained by another neurological cause. It represents a severe neurological complication of pregnancy rather than a separate form of epilepsy. Eclampsia can occur before labour, during labour or after delivery, including in the postpartum period. Seizures are usually generalised tonic-clonic seizures, although presentation can vary.
The underlying cerebral disturbance is associated with severe endothelial dysfunction, altered cerebral vascular regulation, blood-brain-barrier disruption and brain oedema; posterior reversible encephalopathy syndrome is frequently associated with eclamptic seizures on neuroimaging. Importantly, not every person with eclampsia has previously recognised severe hypertension or classic symptoms of Pre-eclampsia, so absence of a prior diagnosis does not exclude the condition. Eclampsia is an obstetric emergency because seizures can cause maternal hypoxia, aspiration, trauma, stroke and cardiovascular instability while simultaneously compromising fetal oxygenation.
The immediate priority during Eclampsia is maternal stabilisation. The person should be protected from injury, positioned to maintain the airway and oxygenation, and assessed for breathing and circulation. Magnesium sulfate is the standard anticonvulsant treatment used to prevent further eclamptic seizures and is preferred over many traditional anticonvulsants because of its effectiveness in this specific context. A further dose may be administered if another seizure occurs according to established protocols, with careful monitoring for toxicity.
Severe hypertension requires prompt treatment using appropriate antihypertensive medication. The airway may require advanced management if consciousness or breathing is compromised. Clinicians also evaluate for complications such as pulmonary oedema, placental abruption, kidney injury, liver dysfunction and low platelets. Magnesium sulfate is not simply a blood-pressure medicine; its principal acute role is seizure prevention and treatment. Calcium gluconate is used as an antidote for clinically significant magnesium toxicity, which is why monitoring of reflexes, respiratory function and urine output is incorporated into treatment protocols.
Once the mother is stabilised, the pregnancy must be assessed and delivery planned. Eclampsia generally indicates that the pregnancy cannot simply be observed indefinitely because the underlying placental disorder persists. However, immediate delivery during an uncontrolled seizure is not necessarily appropriate; maternal resuscitation and stabilisation take priority because fetal outcome depends heavily on restoration of maternal oxygenation and circulation. After stabilisation, the method and timing of delivery depend on gestational age, cervical findings, fetal status, maternal condition and obstetric circumstances.
Vaginal birth may be possible if labour is advanced or induction is appropriate, while caesarean birth may be required when rapid delivery is indicated and vaginal delivery is not feasible. Eclampsia itself is not an automatic indication for one particular mode of birth in every case. Corticosteroids may be considered when preterm delivery is expected, although maternal safety takes precedence when urgent delivery is required.
The neurological basis of Eclampsia overlaps with the pathophysiology of Pre-eclampsia but is not explained simply by a very high blood pressure reading. Cerebral autoregulation normally maintains relatively stable cerebral blood flow despite changes in systemic pressure. In severe hypertensive disease, autoregulatory mechanisms can fail, causing excessive cerebral blood flow, vascular leakage and vasogenic oedema. Endothelial dysfunction and circulating placental factors may further impair cerebral vascular integrity.
Posterior reversible encephalopathy syndrome is characterised by vasogenic oedema that often affects posterior cerebral regions, although imaging abnormalities can occur elsewhere. Neurological symptoms such as severe headache, visual disturbance, confusion or altered consciousness may precede a seizure, but seizures can also occur unexpectedly. Brain imaging is considered when the diagnosis is uncertain, neurological findings are atypical or the person fails to recover as expected, particularly to exclude intracranial haemorrhage, cerebral venous thrombosis or other causes.
Differential diagnosis is important because not every seizure in pregnancy is Eclampsia. Epilepsy, cerebral venous sinus thrombosis, intracranial haemorrhage, metabolic disturbances, central nervous system infection and other neurological disorders can produce seizures. A person with known epilepsy can also have seizures during pregnancy for reasons unrelated to hypertensive disease. Clinicians therefore consider blood pressure, proteinuria, laboratory abnormalities, pregnancy history, neurological examination and the seizure's context.
Nevertheless, when Eclampsia is clinically suspected, treatment with magnesium sulfate should not be unnecessarily delayed while extensive diagnostic testing is pursued, because recurrent seizures carry significant risk. The condition illustrates an important emergency-medicine principle: potentially reversible life-threatening causes are treated promptly while diagnostic clarification continues in parallel.
Maternal complications of Eclampsia can include aspiration pneumonia, hypoxic brain injury, intracranial haemorrhage, stroke, pulmonary oedema, renal failure, hepatic injury, disseminated intravascular coagulation and death. The seizure itself can cause trauma, including injury from falling or striking nearby objects. Fetal risks arise from maternal hypoxia, uteroplacental hypoperfusion, placental abruption and the need for premature delivery. Continuous fetal assessment is therefore often performed after maternal stabilisation.
Some fetal heart-rate abnormalities occurring immediately after a maternal seizure can resolve when maternal oxygenation and circulation improve, so emergency caesarean birth solely because of transient post-seizure fetal changes may not always be necessary. Persistent fetal compromise, however, can require urgent delivery. This distinction emphasises why maternal resuscitation and fetal management are interdependent rather than separate tasks.
Eclampsia can occur postpartum, sometimes after apparently uncomplicated pregnancy and delivery. The postpartum period remains physiologically dynamic, and blood pressure can rise after birth rather than immediately fall. Warning symptoms such as severe headache, visual changes, epigastric pain, breathlessness or confusion should therefore receive urgent medical assessment even after delivery. Magnesium sulfate may be continued for a period after seizure control according to clinical protocol because recurrence remains possible. Antihypertensive treatment and monitoring continue as needed. Follow-up after an eclamptic pregnancy should also address the underlying hypertensive disorder, recovery of kidney and liver function where affected, and longer-term cardiovascular risk. Future pregnancies generally warrant early risk assessment because previous Pre-eclampsia or Eclampsia increases the likelihood of recurrence.
Eclampsia is historically important because seizures in pregnancy were once interpreted through very different medical frameworks, while modern obstetrics recognises their relationship with hypertensive placental disease. The introduction and widespread use of magnesium sulfate transformed management by providing an effective, relatively inexpensive and well-studied anticonvulsant for this setting. Modern care combines rapid maternal stabilisation, seizure control, blood-pressure management, laboratory assessment, fetal surveillance and delivery planning.
Prevention is largely achieved by recognising and managing Pre-eclampsia before seizures occur, including appropriate risk reduction and surveillance in high-risk pregnancies. However, no prevention strategy eliminates all cases. The essential conceptual distinction is that Eclampsia is not synonymous with epilepsy and is not defined merely by a blood-pressure number; it is a pregnancy-associated seizure syndrome requiring urgent treatment and investigation for the underlying hypertensive and neurological processes.
