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  • Rare but serious complication of pregnancy that can result in injury or death of the pregnant person and/or baby
  • Symptoms include seizures, facial twitching, body-wide muscle contractions and relaxations, foam at the mouth
  • Treatment includes medication, vaginal or cesarean delivery of the baby
  • Involves Maternal-Fetal Medicine, High-Risk Pregnancy Program, Obstetrics, Gynecology & Reproductive Sciences



Eclampsia, a rare condition in which a pregnant or postpartum person suddenly experiences seizures, is a medical emergency. It is a serious complication of pregnancy that can lead to injury or death of the pregnant person and/or baby. Eclampsia usually occurs in people with preeclampsia, a condition of high blood pressure and protein in the urine that can develop during pregnancy or in the postpartum period. However, in some cases, eclampsia may arise in a pregnant or postpartum person not previously diagnosed with preeclampsia.

The hallmark symptom of eclampsia is seizures, which can lead to dangerous complications, including difficulty breathing, blood clots, stroke, coma, heart failure, premature birth, and maternal and fetal death.

Eclampsia typically occurs during the final trimester (weeks 28–40) of pregnancy, but it can arise any time after 20 weeks of pregnancy and until 6 weeks after delivery. It can even occur during labor and delivery.

Eclampsia is rare, affecting fewer than 1% of pregnant women with high blood pressure during pregnancy, which includes women with preeclampsia. In the U.S., this means that between 1 and 10 pregnant women out of every 10,000 are affected.

The most effective treatment is to stabilize the person having a seizure and then prepare to deliver the baby, as the condition typically begins to resolve after childbirth. Importantly, treatments for eclampsia are available to help stop seizures, safely lower blood pressure, and deliver the baby safely. Complications, which may lead to injury or death of the mother and/or baby, occur in 5.6% to 14% of women with eclampsia, highlighting the importance of proper diagnosis and treatment.

What is eclampsia?

Eclampsia typically occurs when a pregnant person with preeclampsia (a condition marked by high blood pressure and protein in the urine) begins having seizures. The condition is a life-threatening emergency.

In healthy pregnant persons, blood pressure levels remain normal throughout pregnancy and postpartum. However, in pregnant and postpartum persons who develop high blood pressure and protein in their urine, the diagnosis is a condition called preeclampsia. Preeclampsia may be mild or severe, either of which may advance to eclampsia.

Because doctors cannot predict which patients with preeclampsia will advance to eclampsia, anticonvulsant (anti-seizure) medication may be given to pregnant and postpartum persons with severe preeclampsia to reduce their risk of seizures.

What causes eclampsia?

Doctors aren’t sure what causes eclampsia. It may be related to problems related to the development of the placenta or poor blood flow to the placenta. Genetic factors, inflammatory changes in the body, blood clotting abnormalities, brain inflammation, or hormone imbalances may also be factors.

What are the symptoms of eclampsia?

Seizures are the most notable symptom of eclampsia. Pregnant or postpartum persons may experience seizures that last 1 to 2 minutes. During the seizure, they typically:

  • Experience facial twitching
  • Have a series of rapid, body-wide muscle contractions and relaxations
  • Foam at the mouth
  • Become unconscious for a short period after the seizure
  • Act confused or agitated after regaining consciousness
  • Hyperventilate during seizure recovery
  • Have no memory of the seizure

Some experience seizure-related complications, such as biting their tongues, hitting their heads on the floor (causing head trauma), and breaking bones due to falls.

What are the risk factors for eclampsia?

Pregnant persons are at increased risk of eclampsia if they:

  • Have never been pregnant before
  • Are pregnant with twins or other multiples
  • Have a personal or family history of preeclampsia/eclampsia
  • Are teenagers
  • Are age 35 or older
  • Experienced fetal growth restriction or stillbirth in a previous pregnancy
  • Had placental abruption (the placenta detaching from the uterus) in a previous pregnancy
  • Have a pregnancy affected by fetal growth restriction
  • Have obesity
  • Have pregestational diabetes
  • Have lupus or other autoimmune diseases
  • Have kidney disease
  • Had hypertension before becoming pregnant
  • Have vascular conditions
  • Had in-vitro fertilization (IVF)

How is eclampsia diagnosed?

As soon as a pregnant person with preeclampsia begins experiencing seizures, they may be diagnosed with eclampsia. The seizures may arise suddenly and should be treated immediately.

Doctors may not rely on an extensive medical history, although it’s helpful for them to know that a patient was diagnosed with preeclampsia, has a personal or family history of preeclampsia/eclampsia, or has a known seizure disorder not related to pregnancy or preeclampsia.

It is important to note that many pregnant people who develop eclampsia were previously diagnosed with preeclampsia because they had high blood pressure readings (140/90 mmHg or higher) and protein in their urine, a sign that the kidneys are malfunctioning. Some patients with severe preeclampsia (with blood pressure readings of 160/110 mmHg or higher) may have been prescribed anti-seizure medication to prevent eclampsia, but the treatment is not always effective.

Diagnostic testing may be used to confirm high blood pressure and protein in the urine, check liver function, blood cell count, and look for blood clotting abnormalities, particularly among those not previously diagnosed with preeclampsia. Imaging studies, such as cranial tomography (CT), may be used to rule out other conditions, such as a brain hemorrhage. Other testing may be performed to rule out infection, trauma, or ingestion of a toxic substance.

How is eclampsia treated?

When a pregnant person with eclampsia begins having seizures, they will be treated immediately with magnesium sulfate, an intravenous anticonvulsant medication used to stop or prevent seizures. The patient should also be placed on her side to reduce the risk of aspiration (inhaling food, vomit, or bodily fluids). If magnesium sulfate is not effective, another anticonvulsant medication may be given intravenously, such as a benzodiazepine like diazepam or lorazepam.

In addition, intravenous medication to lower their blood pressure, such as hydralazine or labetalol, and supplemental oxygen to help the patient and baby maintain adequate oxygen levels may also be given.

Ultimately, delivery is usually the most effective way to treat or “cure” eclampsia. Once a person with eclampsia has been stabilized and is not actively having seizures, doctors typically recommend delivering the baby. After an eclamptic seizure, a woman can have a vaginal birth or a Cesarean birth, but in many cases a Cesarean delivery is preferred because it is often quicker than vaginal delivery—the speed of a delivery may minimize potential complications. In some cases, if the patient and the baby have stabilized after the seizure, doctors may give oxytocin to speed labor and vaginal delivery.

After delivery, the patient should continue to receive magnesium sulfate or another anticonvulsant medication for 24 hours. She should be observed closely during this time frame to help avoid complications, such as very high blood pressure, difficulty breathing or additional seizures.

Some patients with eclampsia are given medication to lower their blood pressure when they’re discharged from the hospital. They may need to follow up with their doctors earlier and more frequently, than the typical 6-week post-pregnancy appointment.

What is the outlook for people with eclampsia?

Most people with eclampsia recover and safely deliver their babies. Others may have serious health complications, such as stroke, and their babies may experience severe complications, such as prematurity, brain injury, or neonatal respiratory distress syndrome. In a minority of cases, people and/or babies die from eclampsia.

Some people who develop eclampsia during pregnancy continue to have high blood pressure for 6 to 8 weeks after pregnancy.

People with eclamptic seizures are at increased risk of eclampsia in later pregnancies. Their doctors may prescribe low-dose (baby) aspirin during future pregnancies to reduce this risk. People who have had eclampsia are also at an increased risk of cardiovascular disease, seizures, and cognitive impairment later in life, highlighting the importance of proper diagnosis and treatment.

What makes Yale unique in its treatment of eclampsia?

”Yale Maternal-Fetal Medicine is a regional center with expertise in management of preeclampsia, eclampsia, and other hypertensive disorders that may complicate a current or past pregnancy,” says Katherine Campbell, MD, MPH, a Yale Medicine specialist in maternal-fetal medicine and medical director of Labor & Birth and the Maternal Special Care Unit at Yale New Haven Hospital. “Yale offers 24 hour-7 days a week Maternal-Fetal Medicine coverage of our inpatient Labor and Birth Unit at Yale-New Haven Hospital and we collaborate closely with our neonatal colleagues to help care for our patients and their babies. We provide state of the art care, incorporating multidisciplinary, team-based care in both the outpatient and inpatient setting to manage patients with preeclampsia or eclampsia. We have active research studies to help advance our understanding of the mechanisms underlying this disease, identify novel therapeutics, and provide optimal clinical care at the bedside and after discharge home.”