Alternative names
Toxemia with seizures

Eclampsia is the occurrence of seizures not attributed to another cause during pregnancy, usually after the 20th week.

Causes, incidence, and risk factors

The cause of eclampsia is not well understood. Eclampsia may follow preeclampsia, if that condition cannot be brought under control. Preeclampsia is a serious condition which occurs during pregnancy and is marked by high blood pressure, weight gain, and protein in the urine.

It is difficult to predict which preeclamptic women may go on to have seizures - the hallmark of eclampsia. There is poor correlation between the degree of hypertension present in preeclampsia and the ultimate occurrence of seizures.

The exact cause of preeclampsia has not been identified. Numerous theories of potential causes range from genetic, dietary, vascular (blood vessel), and neurological factors. None of the theories has yet been proven.

Preeclampsia occurs in approximately 5% of all pregnancies. The incidence of eclampsia is approximately 1 out of 2000 to 3000 pregnancies. An increased risk for preeclampsia is associated with first time pregnancies, teenage pregnancies, mothers over the age of 40, African-American women, multiple pregnancies, and women with a history of diabetes, hypertension, or renal (kidney) disease.


  • Seizures  
  • Severe agitation  
  • Unconsciousness for a variable period of time  
  • possible musculoskeletal aches and pains after an event caused by trauma


  • Nondependent edema (swelling of the hands and face which is present upon arising). Some dependent edema - that is, swelling of the feet and ankles - is considered normal with pregnancy.  
  • Unintentional weight gain in excess of 2 pounds per week. It may be a very sudden gain over 1 to 2 days.  
  • Headache which is resistant to treatment with usual pain medications.  
  • Visual disturbances.  
  • Epigastric or upper abdominal pain.

Signs and tests


  • Involuntary movements (tonic-clonic seizures) occur.  
  • The relaxation phase of deep-tendon reflexes may be prolonged.  
  • Breathing (respiration) may cease for brief periods (apnea).  
  • Physical evidence of trauma may be noted.  
  • Infrequently, an eye examination may note retinal changes caused by hypertension.


  • Documented weight gain occurs.  
  • Nondependent edema occurs.  
  • Blood pressure is high (140/90 millimeters mercury or greater) Protein is noted in urine (proteinuria).  
  • The platelet count is less than 100,000/FL (thrombocytopenia).  
  • Liver function tests are elevated.

Eclampsia or preeclampsia may also alter the results of the following tests:

  • Hematocrit  
  • Serum chloride  
  • Uric acid  
  • Creatinine  
  • CBC  
  • Blood differential


Because the risk of eclampsia is unpredictable and often not easily related to physical signs such as the degree of high blood pressure, an anticonvulsant (seizure prevention medication) is usually given to women in labor with preeclampsia. Magnesium sulfate is a safe drug for both the mother and the fetus when used to prevent seizures.

The treatment for preeclampsia is bedrest and delivery as soon as it is safe for the fetus. Patients are usually hospitalized, but occasionally may be managed on an outpatient basis with careful monitoring of blood pressure, urine protein, and weight gain.

Medication may be used to lower the elevated blood pressure. The goal is to manage the condition until 36 weeks of the pregnancy have passed. The condition is then relieved with the delivery of the baby.

Delivery may be induced if any of the following occur:

  • Diastolic blood pressure of greater than 110 mmHg consistently for a 6-hour period  
  • Persistent or severe headache  
  • Epigastric (stomach region) pain  
  • Abnormal liver function tests  
  • Rising serum creatinine  
  • HELLP syndrome  
  • Pulmonary edema (fluid in lungs)  
  • Eclampsia  
  • Thrombocytopenia  
  • Abnormal fetal heart pattern  
  • Failure of fetal growth noted by ultrasound

Delivery is the treatment of choice for eclampsia in a pregnancy over 28 weeks. For pregnancies less than 24 weeks, the induction of labor is recommended, although the likelihood of a viable fetus is minimal.

Prolonging such pregnancies results in maternal complications as well as infant death in approximately 87% of the cases. Pregnancies between 24 and 28 weeks gestation present a “gray zone,” and conservative management may be attempted, with monitoring for maternal and fetal complications.

Expectations (prognosis)

Maternal deaths caused by preeclampsia or eclampsia are rare in the U.S. Fetal or perinatal (close to birth) deaths are high and generally decrease as the maturity of the fetus increases. The risk of recurrent preeclampsia in later pregnancies is approximately 33%. Preeclampsia does not appear to lead to chronic high blood pressure in women.


Preeclampsia may develop into eclampsia - the occurrence of seizures. Eclampsia may lead to complications from trauma or even death. The risk for placenta abruptio is increased with preeclampsia or eclampsia. Fetal complications caused by prematurity at the time of delivery may occur.

Calling your health care provider

Call your health care provider or go to the emergency room if any symptoms of eclampsia or preeclampsia occur during pregnancy. Emergency symptoms include seizures or decreased consciousness.


Although there are currently no known preventive methods, it is important for all pregnant women to obtain early and ongoing prenatal care. This allows for the early recognition and treatment of conditions such as preeclampsia. Adequate treatment of preeclampsia may prevent eclampsia from occuring.

Johns Hopkins patient information

Last revised: December 8, 2012
by Armen E. Martirosyan, M.D.

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