The cause of eclampsia is not well understood. Eclampsia may follow pre-eclampsia, if that condition cannot be brought under control. Pre-eclampsia 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 pre-eclamptic women may go on to have seizures -- the hallmark of eclampsia. There is poor correlation between the degree of hypertension present in pre-eclampsia and the ultimate occurrence of seizures.

The exact cause of pre-eclampsia 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.

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

• seizures
• agitation (severe)
• 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, a swelling of the feet and ankles -- is considered normal with pregnancy.
• weight gain (unintentional) 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.

ECLAMPSIA

• Involuntary movements (tonic-clonic) 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.

PREECLAMPSIA

• 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).
• Elevated liver function tests.

These diseases 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 correlated to physical signs, such as the degree of hypertension or proteinuria, an anticonvulsant (seizure prevention medication) is usually given to women in labor with pre-eclampsia. Magnesium sulfate is a safe drug for both the mother and the fetus when used to prevent seizures.

The treatment of women with pre-eclampsia is bedrest and delivery as soon as viable for the fetus. Patients are usually hospitalized, but occasionally may be managed on an outpatient basis with careful monitoring of blood pressure, urine checks for protein, and weight.

Medication may be used to lower the elevated blood pressures. Optimally, the condition is managed until delivery after 36 weeks can occur.

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 and/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 the presentation of maternal and fetal complications.

Maternal deaths caused by pre-eclampsia or eclampsia are rare in the U.S. Fetal or perinatal deaths are high and generally decrease as the maturity of the fetus increases. The risk of recurrent pre-eclampsia in subsequent pregnancies is approximately 33%. Pre-eclampsia does not appear to lead to chronichigh blood pressure in women.

Pre-eclampsia 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 pre-eclampsia and/or eclampsia. Fetal complications caused by prematurity at the time of delivery may occur.

Call your health care provider or go to the emergency room if any symptoms of eclampsia or pre-eclampsia 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 pre-eclampsia. Adequate treatment of pre-eclampsia may prevent eclampsia from presenting itself.