Eclampsia

Eclampsia is a new-onset generalized seizure in a pregnant or postpartum patient with preeclampsia when another neurologic or metabolic cause does not explain the seizure. It usually occurs at or after 20 weeks of gestation, during labor, or after delivery and can occur as late as 6 weeks postpartum. A previously normal blood pressure does not exclude it; some patients seize before severe hypertension is documented. Preeclampsia causes widespread endothelial dysfunction and abnormal cerebrovascular control. Cerebral vasoconstriction, vasodilation, and blood-brain barrier disruption can produce cerebral edema and neuronal irritability. The seizure is therefore not simply a symptom of high blood pressure. Magnesium sulfate is used because it reduces neuromuscular excitability and helps prevent recurrent seizures, while blood-pressure treatment limits further vascular injury. The immediate threat is maternal hypoxia, aspiration, trauma, and recurrent seizure activity. Fetal oxygenation can also fall when maternal ventilation and uteroplacental perfusion deteriorate.