Eclampsia and Preeclampsia


What Is It?

Preeclampsia is a condition that occurs only during pregnancy, after the 20th week. A woman with preeclampsia develops high blood pressure and protein in the urine, and is often noted to have swelling (edema) of the legs, hands, face or entire body. Eclampsia is a complication of preeclampsia marked by seizures or coma. The condition affects both mother and fetus. In preeclampsia, the mother’s blood vessels constrict (become narrower). This decreases the blood supply to the fetus and placenta (afterbirth), the woman’s kidneys, liver, eyes, brain and other organs.

Preeclampsia and eclampsia are leading causes of illness and death for mothers and newborns. Preeclampsia occurs in approximately 5 percent to 8 percent of pregnant women in the United States. Eclampsia occurs in one of every 200 women with preeclampsia, and is often fatal if not treated.

The cause of preeclampsia remains unknown although many theories have been suggested. However, the following conditions increase the chance that a woman will develop preeclampsia and eclampsia:

  • Chronic (long-lasting) high blood pressure
  • Obesity
  • Diabetes
  • Kidney disease
  • Age under 15 or over 35 years old
  • First pregnancy
  • Multiple gestations (twins, triplets or greater)
  • Lupus or other collagen vascular disease
  • African-American ethnicity
  • Having a sister, mother or daughter who has had preeclampsia


Mild preeclampsia — A woman with mild preeclampsia may not notice any symptoms, or may have only mild swelling of the hands or feet. However, most pregnant women have some degree of swelling, so not all swelling indicates preeclampsia.

Severe preeclampsia — Symptoms can include:

  • Headache
  • Visual changes
  • Nausea and abdominal pain, usually in the upper abdomen
  • Difficulty breathing
  • Pelvic pain
  • Bleeding, such as from the gums or the vagina, or blood in the urine

Eclampsia — Eclampsia causes seizures, which consist of loss of consciousness with jerking movements of the arms and legs and possible loss of control of bladder or bowels.


Because preeclampsia doesn’t always cause noticeable symptoms, it is crucial that all pregnant women see a health-care provider regularly during pregnancy for prenatal care. This gives you the best chance of having preeclampsia diagnosed and treated before it becomes severe. Your doctor or midwife will measure your blood pressure and test your urine for protein at each prenatal visit because abnormal results are the earliest, most common signs of preeclampsia.

Preeclampsia can be especially difficult to detect in women who have a history of high blood pressure (hypertension) before pregnancy. One in four women with high blood pressure develop preeclampsia during pregnancy, so it is essential that these women be monitored closely.

Your doctor or midwife will diagnose preeclampsia or eclampsia depending on your symptoms and the results of tests. Here is how the diagnosis is determined:

  • Mild preeclampsia — Characterized by the following:
    • Blood pressure of 140/90 or above, or a 30-point rise in the systolic value (upper number) or 15 point rise is the diastolic (lower number) over your usual blood pressure, even if the values are not above 140/90
    • Swelling that occurs even when lying down, or weight gain of more than two pounds in a week or a sudden weight gain. (Swelling in the ankle area is considered normal during pregnancy.)
    • Protein in the urine

  • Severe preeclampsia — Characterized by:
    • Blood pressure of 160/110 or higher while on bed rest and in more than one reading separated by at least six hours
    • Protein in the urine of more than 5 grams in a 24-hour period
    • Symptoms such as severe headache, changes in vision, reduced urine output, abdominal pain, fluid in the lungs, pelvic pain and vaginal bleeding
    • Signs of the “HELLP” syndrome, which means the liver and blood-clotting systems are not functioning properly. HELLP stands for Hemolysis (damaged red blood cells), Elevated Liver enzymes (from liver swelling and bleeding), and Low Platelets (cells that help the blood to clot). It occurs in about 10 percent of patients with severe preeclampsia.

  • Eclampsia — The diagnosis of eclampsia is made when a woman with preeclampsia has seizures or goes into a coma. Most eclamptic seizures happen in women who have severe preeclampsia. However, such seizures can occur with mild preeclampsia. Eclampsia can happen during the immediate postpartum period. Approximately 30 percent to 50 percent of patients with eclampsia also have the HELLP syndrome.

Expected Duration

Preeclampsia can begin as early as the 20th week of pregnancy, but it is more likely to develop during the last three months of pregnancy. It usually can be managed with treatment through the rest of pregnancy. If the condition worsens and threatens the health of the mother then the baby has to be delivered. Preeclampsia goes away after delivery. Once eclampsia develops, the best treatment for the mother and the baby is delivery.


Since the cause of preeclampsia is unknown, there is no way to prevent it. Calcium supplements may help to prevent preeclampsia in women whose diets are low in calcium. Research has shown that calcium supplements don’t prevent preeclampsia in women who already get enough dietary calcium. Low-dose aspirin, once thought to prevent preeclampsia, also has been shown not to help.

However, the complications of preeclampsia and eclampsia can be prevented. The U.S. Centers for Disease Control and Prevention found that women who receive prenatal care are seven times less likely to die from preeclampsia and eclampsia than women who do not get any care during pregnancy. Prenatal care is a crucial and lifesaving step in preventing complications and deaths of both the mother and the fetus.


The only cure for preeclampsia and eclampsia is to deliver the baby. However, your doctor or midwife may try to delay delivery to make sure the baby has developed enough to do well outside the womb.

  • Mild preeclampsia — The goal of treating mild preeclampsia is to delay delivery until the fetus is mature enough to live outside the womb. You most likely will be put on bed rest and your doctor or midwife will monitor your blood pressure, weight, urine protein, liver enzymes and the clotting factors in your blood. They also will monitor the well-being and growth of your fetus. Some women need to be hospitalized for adequate treatment and monitoring, while others can remain in bed at home. If you are not hospitalized, you will need to be seen by your health-care providers frequently.

  • Severe preeclampsia — The overall goal is to prevent eclampsia (seizures) and deliver your baby as soon as your physical health allows. Your physical health and well-being will begin returning to normal after the baby is delivered from your womb. Women with severe preeclampsia are hospitalized and usually are treated with magnesium sulfate, a medication to lower the risk of seizures. Magnesium sulfate is usually given intravenously (into a vein) or by injection into a muscle. Medications to lower blood pressure may be needed before delivery.

  • Eclampsia — Seizures generally are treated with intravenous magnesium sulfate. Other antiseizure medications such as lorazepam (Ativan) or phenytoin (Dilantin) may be used, but they don’t work as well to control eclampsia. Once seizures are controlled and the mother’s blood pressure is stabilized, the baby is delivered.

When To Call A Professional

You should see a health-care provider as soon as you become aware you are pregnant. If you have swelling, severe headache, changes in vision, abdominal or pelvic pain, or other symptoms of preeclampsia, see your doctor or midwife immediately.


The outlook for full recovery from preeclampsia is very good. Most women begin to improve within one to two days after delivery, and blood pressure returns to the normal pre-pregnancy range within the next six to 12 weeks.

Prenatal care can dramatically reduce the complications and deaths from preeclampsia. In the United States, between 1991 and 1999, there were 1.8 maternal deaths per 100,000 live births resulting from preeclampsia and eclampsia. Progress in treating eclampsia has saved the lives of both mothers and their newborns. In the United States and Britain, between 1 percent and 2 percent of women who developed eclampsia die and 3 percent of their babies die during or shortly after birth. Maternal death rates from eclampsia in other parts of the world remain may be as high, or greater than, 13 percent.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.