About one in 2,000 pregnant women suffer from eclampsia, a life-threatening emergency that requires immediate care. It is most likely to occur during the third trimester, usually in the days shortly before or after delivery, or even during labor.

Eclampsia is one of the possible complications of severe preeclampsia. It is marked by all of the abnormalities of preeclampsia-including high blood pressure, proteinuria (protein in the urine), generalized edema (swelling), and various other symptoms (see Table 1)-with the addition of seizures. These seizures are classified as ?grand mal,? meaning they affect your entire body and cause severe shaking and unconscious movements.

Eclampsia may cause spasms that restrict blood flow, preventing various organs from receiving enough oxygen. Complications for the mother include premature separation of the placenta, kidney and liver dysfunction and failure, blood clotting problems (can cause serious problems during delivery), and pulmonary edema (increased fluid in the lungs). Almost 2% of women who have eclamptic seizures die. Depending on the age of the fetus, eclampsia causes fetal death in nine to 23% of cases.

Table 1. Preeclampsia-Eclampsia-Indications of Severity
Systolic blood pressure

Diastolic blood pressure
< 150 mmHg

< 100 mmHg
160 mmHg or higher

110 mmHg or higher
Visual disturbancesAbsentPresent
Upper abdominal pain or nausea and vomitingAbsentPresent
ConvulsionsAbsentPresent (eclampsia)
Renal (kidney) functionNormalReduced
Thrombocytopenia (low platelet count)AbsentPresent
Liver function abnormalitiesAbsentPresent
Fetal growth restrictionAbsentPresent

An eclamptic seizure can be frightening for you and your family. Initially, you may have severe headaches and vision problems, and feel disoriented and confused. Typically, seizures begin with twitching of the face, followed by rigidity of the body, muscle contractions, and jerky movements. Your breathing becomes rapid and shallow. Seizures generally last no longer than four minutes. At the end of the seizure, you may experience temporary unconsciousness, confusion, and possibly agitation. You will not remember any of the seizure itself; this, too, can be frightening.

The cause of eclampsia remains unknown, though, theories do exist. Presumably, as blood pressure rises due to preeclampsia, the blood vessels in the brain increase their resistance, which sometimes results in spasms of the vessels. As preeclampsia develops, the resistance in the brain drops, and your brain’s system for regulating blood pressure shifts out of balance. This can cause extra-high blood pressure in the brain leading to edema (swelling) and hemorrhage (bleeding).

Who’s at Risk?

Preeclampsia affects about one of every 20 pregnancies in the and other developed countries. About one out of every 100 women with preeclampsia develops eclamptic seizures.

  • Women with a first pregnancy are 6 to 8 times more susceptible than women with previous pregnancies.
  • Being pregnant with twins increases the risk two- to five-fold.
  • The tendency for preeclampsia is inherited but not predictable. Women whose mothers and sisters had preeclampsia have about a 20% chance of developing the condition themselves. This is four to five times (5 to 7%) greater than the general population.
  • Pregnancy after age 35 (after being pregnant before) increases a women’s risk.
  • Women with a pre-existing condition, such as chronic hypertension, kidney disease, thyroid disease, or diabetes, are more likely to develop preeclampsia.
  • Other conditions and diseases that increase a woman’s risk for preeclampsia include hydatidiform mole (an abnormal pregnancy resulting in a mass of cysts that resemble a bunch of grapes), collagen vascular disease, or antiphospholipid syndrome.

Generally, eclampsia occurs within 4 weeks of giving birth. About 40% of eclamptic seizures occur before labor; 20% during labor; and 40% after delivery. Only rarely does eclampsia occur more than a week after delivery.

If seizures occur within 4 weeks of delivery, eclampsia can be distinguished from epilepsy by the presence of at least two of the following:

  • high blood pressure;
  • proteinuria (protein in the urine);
  • thrombocytopenia (decreased platelets); or
  • raised levels of the enzymes alanine aminotransferase and aspartate aminotransferase.

To protect yourself against potential complications of preeclampsia/eclampsia, you should be screened for the characteristic signs of preeclampsia-hypertension and proteinuria-as early as possible. So, you should begin prenatal care as soon as you know you are pregnant, and you should not miss any scheduled appointments.

If you do develop severe preeclampsia or if you have significant pre-existing conditions (such as chronic hypertension or kidney disease), you will likely be treated at a medical center with facilities and personnel accustomed to managing high-risk pregnancies. Because of the possible dangers to you and your baby, it is important that whatever facility you use has an intensive care nursery. You may also be referred for specialized care.

This HealthMap guides you through the steps you and your doctor may take after you have been diagnosed with preeclampsia/eclampsia. Your treatment varies according to the severity of the disorder, how close you are to term, and whether you have any other health problems.. Learning about this condition helps you actively participate in your treatment. When you see your doctor, raise any questions or concerns you have. You may find it helpful to write questions down before you see your doctor or to take notes during your visits.