Preeclampsia Warning Signs

Key takeaways

• Usually starts: after 20 weeks of pregnancy
• High blood pressure in pregnancy: 140/90 mm Hg or higher
• Most useful single change: Go to every prenatal visit so your blood pressure and urine can be checked.
• Commonest mistake: Dismissing a bad headache or swelling as a normal part of late pregnancy.
• See a doctor if any of the signs under "When to get help" below apply to you.

Why it matters

It can worsen quickly and lead to seizures (eclampsia), stroke or organ damage, and it can begin after delivery, when people are no longer seeing their prenatal team.

The numbers, in one place

Published figures for Preeclampsia Warning Signs

Measure	Figure
Usually starts	after 20 weeks of pregnancy
High blood pressure in pregnancy	140/90 mm Hg or higher
After birth	can appear in the days after delivery and up to about 6 weeks later
Prevention for those at high risk	low-dose aspirin (81 mg) daily after 12 weeks, if your clinician recommends it
Key symptoms	severe headache, vision changes, pain in the upper right belly, sudden swelling of the face or hands, shortness of breath

What helps

• Go to every prenatal visit so your blood pressure and urine can be checked
• Ask whether you should take low-dose aspirin if you have had preeclampsia before, or have chronic high blood pressure, diabetes or kidney disease
• If you are given a home blood pressure monitor, use it as instructed and record the readings
• Tell anyone treating you in the year after birth that you were recently pregnant

What to avoid

• Dismissing a bad headache or swelling as a normal part of late pregnancy
• Starting aspirin on your own without talking to your clinician
• Assuming the danger has passed once the baby is born

In depth

Preeclampsia is thought to begin with problems in how the placenta attaches and develops its blood supply early in pregnancy. A poorly supplied placenta releases substances into the parent's bloodstream that damage the lining of blood vessels throughout the body. That widespread blood vessel injury explains why preeclampsia affects so many organs at once: the kidneys leak protein, the liver can become inflamed, the brain can swell, and the blood's clotting system can be disturbed.

The only cure is delivery of the placenta, which is why the timing of birth is central to treatment. Close to term, delivery is usually recommended. Earlier in pregnancy, teams weigh the risks of the condition worsening against the risks of a premature birth, and may monitor closely in the hospital while giving steroids to help the baby's lungs mature.

Preeclampsia also affects long-term health. Having it is linked to a higher lifetime risk of high blood pressure, heart disease and stroke. Like gestational diabetes, it is now seen as a pregnancy event that should change how your heart health is followed for years afterward.

Signs and symptoms

• Blood pressure readings that are higher than usual at visits or at home
• A headache that does not go away with rest, fluids or acetaminophen (Tylenol)
• Blurred vision, flashing lights, seeing spots or sensitivity to light
• Pain in the upper right belly or under the ribs, sometimes mistaken for heartburn
• Swelling that comes on suddenly in the face, hands or around the eyes, or rapid weight gain
• Nausea or vomiting in the second half of pregnancy, and shortness of breath

Causes and risk factors

• Preeclampsia in a previous pregnancy
• Chronic high blood pressure, kidney disease, diabetes or autoimmune conditions such as lupus
• Twins or more
• A first pregnancy, or a long gap since the last pregnancy
• Obesity, older age at pregnancy, and a family history of preeclampsia
• Pregnancy through in vitro fertilization

How it is checked

Preeclampsia is diagnosed when new high blood pressure after 20 weeks occurs with protein in the urine, or with signs that other organs are affected even without protein, such as low platelets, raised liver enzymes, kidney changes, fluid in the lungs, or headache and vision changes. Blood pressure is checked more than once, and the urine may be tested with a dipstick, a single sample ratio or a 24-hour collection.

Blood tests check platelets, liver and kidney function. The baby is assessed with ultrasound for growth and fluid, and with monitoring of the heart rate. Severity guides decisions: features such as very high blood pressure or organ effects mean hospital care and usually earlier delivery.

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Where to go next

• Preeclampsia Warning Signs: A Beginner-Friendly Start
• Preeclampsia Warning Signs: Common Questions Answered
• Pregnancy and Postpartum: The Complete Guide
• Vaccines During Pregnancy: What the Evidence Actually Says
• Postpartum Depression: What Published Guidance Supports

When to get help

Call your prenatal care provider right away for a headache that will not go away, blurred vision or seeing spots, pain under the ribs on the right, sudden swelling or a blood pressure of 160/110 mm Hg or higher. Call 911 for a seizure, chest pain, trouble breathing, confusion or fainting, during pregnancy or after birth.

Where this comes from

• American College of Obstetricians and Gynecologists — Preeclampsia and High Blood Pressure During Pregnancy
• US Preventive Services Task Force — Aspirin Use to Prevent Preeclampsia and Related Morbidity and Mortality: Preventive Medication
• Eunice Kennedy Shriver National Institute of Child Health and Human Development — Preeclampsia and Eclampsia

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.