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Related & look-alikes

Hypertensive Medical emergency

Eclampsia

Also known as Eclamptic seizures. After 20 weeks, during labor, or in the days after birth.

Eclampsia is the onset of seizures in someone with preeclampsia, and a life-threatening emergency at the severe end of pregnancy blood pressure disorders: the same process that strains the organs reaches the brain and triggers a convulsion. A seizure in a pregnant or recently delivered person means calling 911. Eclampsia is rare, often prevented by treating preeclampsia, and its medicine, magnesium sulfate, is highly effective at stopping and preventing these seizures.

Know the warning signs When to call a provider
How common
About 3 in 10,000
Rare; it develops in fewer than 3% of people with preeclampsia.
When
Second half onward
Before, during, or after labor, sometimes days after birth.
Urgency
Emergency
A seizure in pregnancy or postpartum means calling 911.
Outlook
Good with prompt care
Magnesium sulfate and delivery are highly effective.

This can be a medical emergency. A seizure or convulsions, which is a 911 emergency If this happens, go to the ER or call 911 right away.

Understanding it

What is eclampsia?

Eclampsia is new seizures, generalized tonic-clonic convulsions, in someone with preeclampsia when nothing else explains them, the neurologic emergency at the far end of the spectrum. It is uncommon: roughly 3 in 10,000 pregnancies, and fewer than 3% of people with preeclampsia.

The seizure comes when that vessel injury and high pressure reach the brain and disrupt its blood flow. Warning signs often come first: a severe headache that will not lift, blurred vision or flashing lights, upper-belly pain, or agitation. But not always; sometimes a seizure is the first outward sign, one reason preeclampsia is watched so carefully.

Timing can surprise. Eclampsia strikes before labor, during it, or after birth, and a meaningful share of cases are postpartum, usually within the first 48 hours but occasionally days to a couple of weeks out. That is why the warning signs matter even after your baby arrives.

The response follows a clear sequence: protect the airway and prevent injury during the seizure, give magnesium sulfate to stop it and prevent more (this, not a standard seizure drug, is the treatment), bring down dangerously high blood pressure, then deliver once you are stable. With prompt care, most people recover well.

Symptoms

What are the symptoms?

The defining event is a seizure. Warning signs often precede it, but it can strike unannounced; in anyone with or at risk of preeclampsia, treat them as emergencies.

Early signs

  • A severe or persistent headache
  • Vision changes: blurriness, spots, flashing lights, or temporary loss of vision
  • Pain in the upper belly, under the right ribs
  • Nausea or vomiting
  • Agitation, restlessness, or confusion

Emergency signs — call 911

  • A seizure or convulsions, which is a 911 emergency
  • Loss of consciousness or unresponsiveness
  • Severe confusion or agitation
  • The warning signs above (severe headache, vision changes, upper-belly pain) in someone with or at risk of preeclampsia, since they can precede a seizure

Why it matters

Risks to you and baby

Harm from the seizure itself

A convulsion can injure you, and during it your brain and baby get less oxygen, so protecting the airway and stopping it fast come first.

Stroke and brain injury

The very high pressure behind eclampsia can, in severe cases, cause a stroke, so urgent blood pressure control matters.

Other severe complications

Eclampsia can occur alongside HELLP syndrome, placental abruption, a clotting disorder called DIC, fluid in the lungs, and kidney injury.

Effects on your baby

A seizure cuts oxygen to your baby and can cause distress, and delivery is often preterm. Your baby is watched closely, and birth follows once you are stable.

Why it is an emergency

Untreated, eclampsia can be fatal for mother and baby. That is why any seizure in pregnancy or after birth means calling 911 without delay.

How it's found

How is it diagnosed?

Eclampsia is a clinical diagnosis: a seizure in someone with preeclampsia, once other causes are ruled out. The workup also gauges severity and hunts for related complications.

Clinical recognition

A witnessed generalized seizure in a pregnant or recently delivered person with signs of preeclampsia points straight to eclampsia.

Blood pressure measurement

Blood pressure is usually high, often in the severe range (160/110 or above), which supports the diagnosis and guides treatment.

Blood and urine tests

Check for severe features and complications such as HELLP syndrome, kidney injury, and clotting problems.

Ruling out other causes

Other seizure causes, such as epilepsy or stroke, are weighed, especially if the picture is atypical.

Emergently, whenever a seizure occurs in pregnancy or postpartum. Treatment starts at once and does not wait for every test result.

Treatment

How is it managed?

Eclampsia is a medical emergency handled in a clear order: stop and prevent seizures, control blood pressure, and deliver once you are stable.

Treatment paths

Emergency care protects the airway and prevents injury during the seizure. Intravenous magnesium sulfate stops it and prevents recurrence. Medication controls dangerously high blood pressure, and once you are stable, delivery is arranged at any gestational age.

Medication

Magnesium sulfate is the cornerstone. Severe-range blood pressure is treated with labetalol, hydralazine, or nifedipine.

Monitoring

You and your baby are monitored intensively: magnesium levels, blood pressure, reflexes, and fetal heart rate.

Can it recur?

After eclampsia, future pregnancies carry a higher risk of preeclampsia (around 25%) and a small risk of eclampsia again (around 2%); good prenatal care, blood pressure control, magnesium for severe preeclampsia, and low-dose aspirin all lower it.

What you can do

Can it be prevented?

  • Catch and treat preeclampsia early

    The surest way to prevent eclampsia is to catch and manage preeclampsia before it turns severe, which is what prenatal visits and blood pressure checks are for.

  • Magnesium sulfate for severe preeclampsia

    When preeclampsia has severe features, magnesium sulfate during labor and delivery sharply reduces the chance of a seizure.

  • Low-dose aspirin when indicated

    For those at higher risk, low-dose aspirin lowers the chance of preeclampsia in the first place, and so, indirectly, of eclampsia.

Who is more at risk

Risk factors

Preeclampsia, especially with severe features
The central risk factor. Eclampsia complicates preeclampsia, so anything that raises preeclampsia risk raises this too.
The preeclampsia risk profile
A first pregnancy, chronic high blood pressure, diabetes, kidney disease, autoimmune conditions, and carrying multiples all increase risk.
Age and other factors
Being under 20 or over 35, obesity, and a family history of preeclampsia add to the risk.
Limited prenatal care
Missed chances to catch and treat preeclampsia raise the odds it progresses to eclampsia.

Do not wait

When to call your provider or 911

  • Call 911 for any seizure during pregnancy or after birth, or if someone becomes unresponsive.
  • Seek emergency care for the warning signs of severe preeclampsia, a severe headache, vision changes, upper-right belly pain, or sudden severe swelling, since these can precede a seizure.
  • If you witness a seizure, call 911, help the person lie on their side, protect them from injury, and do not put anything in their mouth or restrain them.
  • Watch for these warning signs in the days and weeks after birth too, since eclampsia can occur postpartum.
  • If you have preeclampsia, follow your provider's instructions closely and do not delay care for new or worsening symptoms.

Talking to your team

Questions to ask your provider

  • Do I have preeclampsia with severe features, and what is my risk of a seizure?
  • Should I be receiving magnesium sulfate to prevent seizures?
  • What warning signs mean I should call 911 rather than wait?
  • What is the plan and timing for delivery?
  • What should I and my family watch for after I go home?
  • In a future pregnancy, what can lower my risk of this happening again?

Keep reading

More on eclampsia

All pregnancy guides articles

Good to Know

Eclampsia FAQs

Common questions about eclampsia, answered.

Is eclampsia the same as epilepsy?

No. Epilepsy is a chronic seizure disorder; eclampsia is seizures caused by preeclampsia. The difference drives treatment: eclampsia is treated and prevented with magnesium sulfate, not standard epilepsy medicines.

Can eclampsia happen without any warning?

Yes. Warning signs like a severe headache, vision changes, or upper-belly pain often come first, but not always; sometimes a seizure is the first sign. That unpredictability is why preeclampsia is watched closely and treated before it turns severe.

Can it happen after I have delivered?

Yes. A significant share occurs after birth, usually within 48 hours but sometimes days to a couple of weeks later. Do not dismiss a severe headache, vision changes, or belly pain postpartum; get emergency care.

What should I do if someone is having a seizure?

Call 911 right away. Help them onto their side to keep the airway clear, move away anything they could hit, and cushion their head if you can. Do not restrain them or put anything in their mouth. Note how long the seizure lasts for the medical team.

Will my baby be okay?

A seizure briefly cuts oxygen to your baby, so your baby is watched closely and delivery follows once you are stable. Many babies do well, though birth is often preterm. Prompt treatment gives the best outcome for you both.

Why magnesium sulfate instead of a regular seizure medication?

Because studies show magnesium sulfate beats standard anticonvulsants at both treating and preventing eclamptic seizures. It is the established, evidence-based treatment for this condition.

Will it happen again in my next pregnancy?

Your risk of preeclampsia next time is elevated (around 25%), while eclampsia specifically stays low (around 2%). The same measures that prevent eclampsia lower it.

How is eclampsia prevented?

Mainly by finding and treating preeclampsia early. When it does carry severe features, magnesium sulfate during labor and delivery greatly cuts the seizure risk, and low-dose aspirin lowers the odds of preeclampsia to begin with.

Medically Reviewed · Updated

Reviewed by Dr. Grace Lin, MD, FACOG · OB-GYN

Obstetrician-gynecologist focused on reproductive and sexual health for women: pregnancy, BV, yeast, trichomoniasis and HPV/cervical screening. Our editorial guidelines →

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