If the complication of multi-organ failure ensues, signs and symptoms of those failing organs will appear, such as abdominal pain, jaundice, shortness of breath, and diminished urine output. Onset
The seizures of eclampsia typically present during pregnancy and prior to delivery (the antepartum period), but may also occur during labor and delivery (the intrapartum period) or after the baby has been delivered (the postpartum period). If postpartum seizures develop, it is most likely to occur within the first 48 hours after delivery. However, late postpartum seizures of eclampsia may occur as late as 4 weeks after delivery. Characteristics
Eclamptic seizure is typically described as a tonic–clonic seizure which may cause an abrupt loss of consciousness at onset. This is often associated with a shriek or scream followed by stiffness of the muscles of the arms, legs, back and chest. During the tonic phase, the mother may begin to appear cyanotic. This presentation lasts for about a minute, after which the muscles begin in jerk and twitch for an additional one to two minutes. Other signs include tongue biting, frothy and bloody sputum coming out of the mouth. Complications
There are risks to both the mother and the fetus when eclampsia occurs. The fetus may grow more slowly than normal within the womb (uterus) of a woman with eclampsia, which is termed intrauterine growth restriction and may result in the child appearing small for gestational age or being born with low birth weight. Eclampsia may also cause problems with the placenta.
Following intramuscular administration the onset of action is about one hour and lasts for three to four hours. Magnesium is excreted solely by the kidneys at a rate proportional to the plasma concentration (concentration in the blood) and glomerular filtration (rate at which the blood is filtered through the kidneys). Magnesium sulfate is associated with several minor side effects; serious side effects are uncommon, occurring at elevated magnesium serum concentrations greater than 7.0 mEq/L. Serious toxicity can be counteracted with calcium gluconate.Even with therapeutic serum magnesium concentrations, recurrent convulsions may occur, and additional magnesium may be needed, but with close monitoring for respiratory, cardiac, and neurological depression. If magnesium administration with resultant high serum concentrations fails to control convulsions, the addition of other intravenous anticonvulsants may be used and  intubation and mechanical ventilation may be initiated. It is important to avoid magnesium toxicity, including thoracic muscle paralysis, which could cause respiratory failure and death. Magnesium sulfate results in better outcomes than diazepam, phenytoin or a combination of chlorpromazine, promethazine, and pethidine. Blood pressure management
Blood pressure control is used to prevent stroke, which accounts for 15 to 20 percent of deaths in women with eclampsia. The agents of choice for blood pressure control during eclampsia are hydralazine or labetalol. This is because of their effectiveness, lack of negative effects on the fetus, and mechanism of action. Blood pressure management is indicated with a diastolic blood pressure above 105–110 mm Hg.