Top of the page
Pre-eclampsia is high blood pressure after 20 weeks of pregnancy that may affect the pregnant person's organs or the baby. Severe pre-eclampsia can lead to dangerous seizures (eclampsia). Pre-eclampsia usually goes away after the baby is delivered. But symptoms may last a few weeks or more and can get worse (or show up) after delivery.
Experts don't know the exact cause of pre-eclampsia. It seems to start because the placenta doesn't grow the usual network of blood vessels deep in the uterine wall. This leads to poor blood flow in the placenta. It's not clear what causes this placenta problem and why the birth parent then develops high blood pressure.
Mild pre-eclampsia usually doesn't cause symptoms. But it may cause rapid weight gain and sudden swelling of the hands and face. Severe pre-eclampsia causes symptoms such as a very bad headache and trouble seeing and breathing. It also can cause belly pain and decreased urination.
Pre-eclampsia is usually found during a routine prenatal visit. That's one reason it's important to go to all of your prenatal visits. You need to have your blood pressure checked often. Your blood pressure is measured at each prenatal visit. A sudden increase in blood pressure often is the first sign of a problem.
You'll also be weighed and may have a urine test at each visit to look for signs of pre-eclampsia. People who are at high-risk for pre-eclampsia may have other tests too.
If tests suggest that you have pre-eclampsia, you'll be carefully checked for the rest of your pregnancy. Your baby's health also will be closely watched. The more severe your condition is, the more often you'll need testing. This might range from once a week to daily.
If you have mild pre-eclampsia that isn't quickly getting worse, home care may be enough. You may only have to reduce your level of activity, watch how you feel, and have frequent office visits and testing.
For severe pre-eclampsia, you may need to be in the hospital. You may get medicines to lower your blood pressure and to prevent seizures. You also may get medicine to help prepare your baby's lungs for birth.
But symptoms may last a few weeks or more and can get worse after delivery. Your healthcare provider will try to deliver your baby when the baby has grown enough to be ready for birth. But sometimes a baby has to be delivered early to protect the health of the birth parent or the baby. If this happens, your baby will get special care for premature babies.
Health Tools help you make wise health decisions or take action to improve your health.
Some things increase your risk of pre-eclampsia. For example, your risk is higher if you:
Lowering your blood pressure helps to prevent pre-eclampsia. If you have chronic high blood pressure, you can lower your blood pressure before pregnancy by:
When you are pregnant, regular checkups are important. They let your healthcare provider find and treat problems early. With prompt treatment, you are more likely to prevent severe and possibly life-threatening pre-eclampsia.
To reduce your risk for pre-eclampsia, your healthcare provider may recommend that you take low-dose aspirin during the second and third trimesters of your pregnancy.
Mild pre-eclampsia usually doesn't cause symptoms. But it may cause symptoms such as:
Severe pre-eclampsia can cause:
Severe pre-eclampsia can lead to seizures (eclampsia). Eclampsia is life-threatening for both pregnant person and their baby.
Pre-eclampsia can be mild or severe. It may get worse gradually or quickly. It affects your blood pressure, and can also affect your placenta, liver, blood, kidneys, and brain.
If your condition becomes dangerous enough that delivery is necessary but you don't go into labour, your healthcare provider may induce labour. Or they will deliver the baby with surgery (caesarean section). Symptoms of pre-eclampsia may last a few weeks or more and can get worse after delivery. Rarely, symptoms of pre-eclampsia don't show up until days or even weeks after childbirth.
After you've had pre-eclampsia, you have a higher-than-average risk of heart disease, stroke, and kidney disease. This may be because the same things that cause pre-eclampsia also cause heart and kidney disease. To protect your health, work with your healthcare provider on living a heart-healthy lifestyle and getting the checkups you need.
When you have pre-eclampsia, it's very important to get treatment. That's because both you and your baby could suffer life-threatening problems that involve your:
The earlier in the pregnancy that pre-eclampsia starts and the more severe it gets, the greater the risk of preterm birth. A preterm birth can cause problems for the newborn.
An infant born before 37 weeks may have trouble breathing because of immature lungs (respiratory distress syndrome).
A newborn affected by pre-eclampsia may also be smaller than normal. This is because the baby can't get enough nutrition due to poor blood flow through the placenta.
Share this information with your partner or a friend. They can help you watch for warning signs.
Call 911 anytime you think you may need emergency care. For example, call if:
Seek urgent, immediate medical care at the hospital if:
If you have mild high blood pressure or mild pre-eclampsia, you may not have any symptoms. It's important to see a health professional regularly throughout your pregnancy.
Symptoms such as heartburn or swelling in the legs and feet are normal during pregnancy. They usually aren't symptoms of pre-eclampsia. You can discuss these symptoms with your healthcare provider or midwife at your next scheduled prenatal visit. But if swelling occurs along with other symptoms of pre-eclampsia, contact your healthcare provider or midwife right away.
Pre-eclampsia is usually found during regular prenatal checkups. That's one reason it's important to go to all of your prenatal visits. Tests are done at each visit to check for pre-eclampsia, including these tests:
Blood pressure is always watched closely during pregnancy.
Too much protein in the urine is a sign of kidney damage caused by pre-eclampsia.
Rapid weight gain can be a sign of pre-eclampsia.
People who are at high risk for pre-eclampsia may also have other tests, including:
Blood tests may be done to check for problems such as HELLP syndrome and kidney damage.
If tests suggest that you have pre-eclampsia, you'll be carefully checked for the rest of your pregnancy. Your baby's health also will be closely watched. The more severe your pre-eclampsia is, the more often you'll need testing. This might range from once a week to daily.
Tests commonly used include:
If you have mild pre-eclampsia that isn't quickly getting worse, home care may be enough. You may only have to reduce your activity, watch how you feel, and have frequent office visits and testing.
For severe pre-eclampsia, or for pre-eclampsia that is quickly getting worse, you may need to be treated in the hospital. This often includes taking medicine and keeping a close watch on you and your baby.
Severe pre-eclampsia is treated with magnesium sulfate. This medicine can stop a seizure and can prevent seizures.
Your healthcare provider will try to deliver your baby when the baby has grown enough to be ready for birth. But sometimes a baby has to be delivered early to protect the health of the birthing parent or the baby. If this happens, your baby will get special care for premature babies.
A vaginal delivery is usually safest for the pregnant person. It is tried first if the pregnant person and the baby are both stable. A caesarean section (C-section) is needed if pre-eclampsia is quickly getting worse or the baby can't safely handle labour contractions.
If you have moderate to severe pre-eclampsia, your risk of seizures (eclampsia) continues for the first 24 to 48 hours after childbirth. So you may keep getting magnesium sulfate for 24 hours after delivery.
If your blood pressure is still high after delivery, you may be given a blood pressure medicine. You will have regular checkups with your healthcare provider.
If you didn't have high blood pressure before pregnancy, your blood pressure is likely to return to normal a few days after delivery.
Rarely, symptoms of pre-eclampsia don't show up until days or even weeks after childbirth.
After having pre-eclampsia, you have a higher risk for heart disease, stroke, and kidney disease. To protect your health, work with your healthcare provider to build heart-healthy habits and get the checkups you need.
If you have pre-eclampsia, you may take medicine to:
Lowering high blood pressure doesn't prevent pre-eclampsia from getting worse. That's because high blood pressure is only a symptom of pre-eclampsia. It's not a cause. Your healthcare provider may recommend blood pressure medicine if your blood pressure reaches high levels that may be dangerous to you or your baby.
Magnesium sulfate is usually started before delivery and continued for 24 hours after delivery for people who have:
When possible, steroid medicine is given to the birth parent before a premature birth. It helps the baby's lungs to mature over a 24-hour period. This lowers the baby's risk of breathing problems after birth.
Adaptation Date: 9/21/2022
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
To learn more about Healthwise, visit Healthwise.org.
© 1995-2022 Healthwise, Incorporated. All rights reserved. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.