Reviewed on 11/21/2022

What Are Eclampsia and Preeclampsia During Pregnancy?

Pregnancy Complications
An expectant mother may experience high blood pressure (preeclampsia), which increases the risk of preterm delivery and other potential dangers for the baby.
  • Eclampsia is a life-threatening complication of pregnancy.
  • Eclampsia is a condition that causes a pregnant woman, usually previously diagnosed with preeclampsia (high blood pressure and protein in the urine), to develop seizures or coma. In some cases, seizures or coma may be the first recognizable sign that a pregnant woman has had preeclampsia.
  • Key warning signs and symptoms for the development of eclampsia in a woman previously diagnosed with preeclampsia include
  • There has never been any evidence to suggest an orderly evolution of disease beginning with mild preeclampsia with progression to severe preeclampsia and ultimately to eclampsia. The disease process can be recognized in its mildest form and remain so throughout pregnancy, or it can present as full-blown eclampsia.
  • Less than one in 100 women with preeclampsia will develop eclampsia (characterized by seizures and/or coma).
  • Up to 20% of all pregnancies are complicated by high blood pressure. Complications resulting from high blood pressure, preeclampsia, and eclampsia may account for up to 20% of all maternal deaths.
  • Toxemia of pregnancy is a common name formerly used to describe preeclampsia and/or eclampsia.

What Are the Warning Signs and Symptoms of Eclampsia?

The most common symptom of eclampsia is seizures or convulsions. Similar to preeclampsia, other changes and symptoms may be present and vary according to the organ system or systems that are involved. These changes can affect the mother, the baby, or more commonly both mother and baby together. Some of these following symptoms may be perceived by the pregnant woman, but, more commonly, she is unaware that she has this disease:

  • The most common sign of preeclampsia is elevated blood pressure which is also found in eclampsia. Again, the patient may be unaware that she is hypertensive.
  • Blood pressure may be only minimally elevated, or it can be dangerously high. The degree of blood pressure elevation varies from woman to woman, and also varies during the progression and resolution of the disease process. Some women never have significant blood pressure elevation (including approximately 20% of women with eclampsia).
  • A common belief is that the risk of eclampsia rises as blood pressure increases above 160/110 mm Hg.
  • The kidneys may be unable to filter the blood efficiently. There may also be an abnormal excretion of protein in the urine. The first sign of excess urinary protein is usually determined on a urine specimen obtained at the time of a routine prenatal visit. It is unusual for a patient to experience symptoms related to excess urinary protein loss. In rare cases, there may be the excretion of a large amount of urinary protein.
  • Nervous system changes can include blurred vision, seeing spots, severe headaches, convulsions, and, occasionally, blindness. Any of these symptoms require immediate medical attention, preferably at a hospital that provides obstetrical care, as the emergent delivery of the infant may be required.
  • Changes that affect the liver can cause pain in the upper abdomen. This pain may be confused with the pain of indigestion or gallbladder disease. Other more subtle changes that affect the liver can alter platelet function, thus compromising the ability of the blood to clot. Excess bruising may be a sign of impaired platelet activity.
  • Hypertension which is characteristic of preeclampsia can diminish placental blood flow, thus impairing fetal development. As a result, the baby may not grow properly and may be smaller than anticipated. In severe cases, fetal movements may be lessened as a result of impaired oxygenation of the fetus. A patient should call her physician immediately if she notices a marked decrease in fetal movement.

What Causes Eclampsia?

  • No one knows what exactly causes preeclampsia or eclampsia, although abnormalities in the endothelium (the inner layer of blood vessel walls) have been considered as a potential cause.
  • Since the exact cause of preeclampsia or eclampsia is poorly understood, it is not possible to effectively predict when preeclampsia or eclampsia will occur or to enact any preventative measures that might prevent these problems from developing.
  • Preeclampsia usually occurs during an initial (first) pregnancy.

What Are the Risk Factors for Eclampsia?

  • Preeclampsia also occurs more frequently in women with multiple gestations, who are older than 35 years, who had high blood pressure prior to pregnancy, who are diabetic, and who have other medical problems (such as connective tissue and kidney diseases).
  • Obese women have a higher risk of preeclampsia and eclampsia than women of normal weight.
  • For unknown reasons, African American women are more likely to develop preeclampsia and/or eclampsia than white women.
  • Preeclampsia occurs more frequently within families, although a genetic basis for this has not been determined.
  • Preeclampsia is associated with disorders of the placenta, such as excess or diminished placental mass or an abnormal position of the placenta on the wall of the uterus.
  • Preeclampsia is associated with hydatidiform molar pregnancies, in which normal placental or fetal tissue may be absent.
  • Nothing can be done pre-emptively to prevent the development of preeclampsia or eclampsia.
  • Other risk factors for eclampsia include lower socioeconomic status, teen pregnancy, and poor outcomes during previous pregnancies (including fetal death or intrauterine growth restriction).

When to Seek Medical Care for Eclampsia

  • If a pregnant woman has questions regarding her health or that of her baby.
  • If a pregnant woman has severe or persistent headaches or any visual disturbance, such as double vision or seeing spots (This may be a harbinger of impending eclampsia).
  • If, during pregnancy, the blood pressure rises above 160/110 mm Hg.
  • If a pregnant woman has severe pain in the middle of their abdomen or on the right side of the abdomen under the rib cage. (This may indicate swelling and possible rupture of the liver).
  • If there is any unusual bruising or bleeding during pregnancy.
  • If there is excessive swelling or weight gain during pregnancy.
  • If there has been a marked decrease in fetal activity.
  • If increasing vaginal bleeding or severe abdominal cramping is noted during pregnancy.

Is There a Test to Diagnose Eclampsia?

If any of the previously mentioned symptoms are experienced, a healthcare professional should be notified immediately.  If home blood pressure monitoring is being performed, the readings, if elevated, should be reported to the doctor.  It is likely that a visit to the doctor's office or the hospital may be necessary.

  • All signs, symptoms, and concerns should be reported to the healthcare professional. Blood pressure, weight, and urine protein will be determined at every prenatal visit.
  • If a healthcare professional suspects the possibility of preeclampsia, they will order blood tests to check a platelet count, as well as liver and kidney function. The healthcare professional may order a 24-hour urine collection to check for total protein in the voided specimen. The results of the blood tests should be available within 24 hours (if sent to an outside laboratory), or within several hours if performed at a hospital.
  • The well-being of your baby should be checked by monitoring the rate and rhythm of the fetal heart.
  • Further evaluations of fetal well-being may include non-stress testing, a biophysical profile (ultrasound), and an ultrasound to measure the growth of the baby (if it has not been done within the previous 2-3 weeks).
  • Ancillary studies may include ultrasound, CT scan, or MRI scan of the maternal head to rule out a stroke.

What Medications Treat Eclampsia?

Once eclampsia develops, the only treatment is delivery of the baby (if eclampsia occurs prior to delivery). Eclampsia can develop following delivery, typically within the first 24 hours postpartum. Rarely, the onset of post-partum eclampsia can be delayed and occur up to one week following delivery. There is no cure for eclampsia other than the delivery of the infant.

Seizure treatment

  • Intravenous magnesium sulfate is the pharmacologic treatment of choice once a seizure occurs. This medication diminishes the chance of recurrent seizures. Magnesium treatment is continued for a total of 24 to 48 hours following the last recorded seizure. Patients may receive magnesium in an intensive care or high-risk labor and delivery unit.  Close observation of the patient is mandatory while she is receiving magnesium sulfate.  During the infusion of magnesium sulfate, the patient will be given supplemental intravenous fluids.  They will also require an in-dwelling urinary catheter in order to monitor urinary output.
  • Occasionally, seizures recur despite the utilization of intravenous magnesium sulfate.  In such cases, treatment with a short-acting barbiturate such as sodium amobarbital may be necessary to "break" or stop the seizure.  Other medications including diazepam (Valium) or phenytoin (Dilantin) may also be used.

Once the mother's condition is stabilized following a seizure, the physician will prepare for the emergent delivery of the infant. This can occur by either cesarean section or induction of labor and vaginal delivery. If the patient is already in labor, labor can be allowed to progress provided there is no evidence that the baby has become "distressed " or compromised by the seizure.

High blood pressure medication

  • Patients may require medication to treat high blood pressure during labor and/or after delivery. Hydralazine (Apersoline), labetalol (Normodyne, Trandate), and nifedipine are commonly used products to reduce blood pressure to systolic levels below 160 mm Hg. It is unusual to require medication for high blood pressure beyond six weeks post-partum unless the patient has a problem with hypertension that is unrelated to the pregnancy.

Medication to deliver the baby

The closer the patient is to her due date, the more likely her cervix will be favorable for delivery, and that induction of labor will be successful. Sometimes medications, such as oxytocin (Pitocin), are given to induce or shorten labor.

  • If the pregnancy is less than 34 weeks of gestational age, it is less likely that induction of labor will be successful (although induction is still possible). More commonly a Cesarean section will be necessary to forestall a bad outcome.
  • If the baby shows signs of compromise, such as decreased fetal heart rate, an immediate cesarean delivery should be performed.
  • Some patients may be given intramuscular steroids to mature the fetal lungs if the fetal gestational age is less than 32 weeks.

What Is the Prognosis for a Woman with Eclampsia?

Most women will have good outcomes for their pregnancies, even when complicated by preeclampsia or eclampsia. Some women will continue to have problems with their blood pressure and will need to be followed closely after delivery. About 25% of women who have had eclampsia will have elevated blood pressure in a subsequent pregnancy, and about 2% will develop eclampsia.

Most babies do well. Babies born prematurely will usually stay in the hospital longer. A rule of thumb is to expect the baby to stay in the hospital until its due date.

Unfortunately, a few women and babies experience life-threatening complications from preeclampsia or eclampsia. Complications in babies are generally related to prematurity, and outcomes for both mothers and babies are significantly worse in developing countries. The maternal mortality (death) rate from eclampsia in developed counties ranges from 0% to 1.8% of cases. Most of the cases of maternal death are complicated by a condition known as HELLP syndrome, which is characterized by hypertension, hemolytic anemia, elevated liver function tests (LFTs), and a low platelet count.

Just as there were no tests to predict or prevent eclampsia, there are no tests to predict whether preeclampsia or eclampsia will recur in a subsequent pregnancy. Unfortunately, in a small number of women, preeclampsia and/or eclampsia will recur. This change seems to increase if the preeclampsia or eclampsia was particularly severe in the previous pregnancy, occurred very early in that pregnancy (late second trimester or early third trimester), or there is a new father for the subsequent pregnancy. Because there are no tests to predict recurrent preeclampsia/eclampsia, a previously affected patient should be followed more closely during a subsequent pregnancy.

Pre-eclampsia Signs and Symptoms During Pregnancy

The various changes and symptoms that occur with preeclampsia vary according to the organ system or systems that are affected. These changes can affect the mother only, baby only, or more commonly affect both mother and baby. Some of these symptoms give the woman warning signs, but most do not. When they do the woman may experience:

  • Swelling in the legs or the face
  • Rapid weight gain
  • Headaches
  • Pain in the upper abdomen (liver pain)
  • High blood pressure
Reviewed on 11/21/2022
Medically reviewed by Wayne Blocker, MD; Board Certified Obstetrics and Gynecology


Ross, M.G., MD. "Eclampsia." Medscape. Updated Jul 07, 2016.