• Also Known As:
  • Toxemia
  • Pregnancy-induced Hypertension
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What is preeclampsia?

Preeclampsia is one of the most serious conditions affecting pregnant women. It is diagnosed when a pregnant woman experiences new or worsening high blood pressure (hypertension), protein in her urine (proteinuria), and/or swelling (edema) of the hands, feet and/or face. In severe cases, there may be damage to the kidneys or liver, buildup of fluid in the lungs, changes in vision and/or severe headaches. In the United States, about 5% to 8% of pregnant women develop preeclampsia.

The exact cause of preeclampsia is not known, but research indicates it may be related to abnormal development of the uterine blood vessels that supply the placenta, resulting in narrowed blood vessels and inadequate blood flow to the placenta.

High blood pressure (greater than140/90 mm Hg noted on more than two occasions or four hours apart) during pregnancy is called gestational hypertension that may develop after week 20. If not treated in a timely manner, it may lead to preeclampsia, which generally can occur in the third trimester (about 28 weeks). Preeclampsia is high blood pressure with leakage of protein from the kidneys into the urine. It may lead to reduced blood flow to the placenta, separation of the placenta from the uterus (placental abruption), premature delivery, or future cardiovascular disease.

Rarely, preeclampsia can occur after childbirth. Postpartum preeclampsia is typically diagnosed within 48 hours after delivery, but it can happen up to 6 weeks later. The risk factors and symptoms are very similar to those associated with preeclampsia during pregnancy.

Untreated preeclampsia is dangerous because it can harm the mother’s organs and lead to seizures. Although rare, these pregnancy-related seizures, called eclampsia, can be life-threatening for the mother and her baby if not treated right away. About one out of every 200 women with untreated preeclampsia progresses to eclampsia.

It is important to attend all prenatal checkups because some women with preeclampsia may have no symptoms and because preeclampsia sometimes causes symptoms that are very similar to those of normal pregnancy. During the checkups, your healthcare practitioner will perform a physical exam and order laboratory tests to look for “silent” signs of preeclampsia, like high blood pressure and protein in the urine.


About Preeclampsia

Risk Factors

Although preeclampsia is most common in first pregnancies, a woman who had preeclampsia in a previous pregnancy is 7 times more likely to develop preeclampsia in a later pregnancy.

While researchers are still trying to establish the exact cause of preeclampsia, it is associated with certain risk factors.

You may be at high risk if you:

You may be at moderate risk for preeclampsia if you:

  • Are pregnant for the first time or first pregnancy with a new partner
  • Are obese (pre-pregnancy body mass index over 30)
  • Have a family history of preeclampsia (e.g., a mother or sister who had the condition)
  • Are older than age 35
  • Are African American

Other risk factors include:

  • Pregnancy resulting from egg donation, donor insemination, or in vitro fertilization
  • Interval of pregnancies – having babies in less than two years or more than 10 years apart
  • Having an excessive clotting disorder (thrombophilia)

Signs and Symptoms

Preeclampsia can develop with no obvious symptoms. If symptoms are present, they may seem similar to those experienced during normal pregnancy. For example, weight gain and swelling are preeclampsia symptoms that also occur during normal pregnancies. High blood pressure is a sign of preeclampsia that typically goes unnoticed until a healthcare practitioner discovers it during a prenatal visit.

Symptoms of preeclampsia may include:

  • Sudden weight gain of more than 2 pounds in a week
  • Swelling of face and hand (edema)
  • Persistent and/or severe headaches
  • Changes in eyesight: seeing spots, blurry or temporary loss of vision, flashing light sensations, or light sensitivity
  • Nausea or vomiting, especially in the second half of pregnancy
  • Urinating less (decreased amount of urine)
  • Difficulty breathing, shortness of breath
  • Shoulder pain or stomach pain or pinching, especially in the upper right side of your abdomen or when laying on your right side

Some signs of preeclampsia that may be detected during a health exam include:

  • Elevated blood pressure
  • Unusually strong leg reflexes (i.e., when a healthcare practitioner taps your knee with a rubber hammer), sometimes preceding seizures
  • Protein in urine
  • Decreased platelet count (only in HELLP syndrome, see Complications below)
  • Abnormal liver tests (only in HELLP syndrome)

If you have symptoms associated with preeclampsia or notice sudden changes in your pregnancy, it is important that you let your healthcare provider know right away. Untreated preeclampsia is a serious condition that can be fatal for you and your baby. It is important to attend all prenatal checkups and seek medical attention if symptoms arise.


If left untreated, preeclampsia can lead to serious and life-threatening complications for you and your baby.

Possible complications include:

  • Seizure (eclampsia)
  • Damage to liver, kidneys, lungs, heart, and/or eyes
  • Stroke
  • Low birth weight in the baby
  • Premature delivery, which can cause health problems in the baby
  • Placental abruption (the placenta detaches from the uterus before the baby is born, causing bleeding and sometimes early delivery or stillbirth)

Rarely, preeclampsia can progress to HELLP syndrome, another life-threatening condition for mother and baby. It is called HELLP because it is defined by the breakdown of red blood cells (Hemolysis), Elevated Liver enzymes, and a Low Platelet count.

Women with a history of preeclampsia are also more likely to develop heart disease and kidney disease later in life.


There is currently no single reliable test for preeclampsia in pregnancy. The American College of Obstetricians and Gynecologists (ACOG) recommends that healthcare practitioners screen for preeclampsia in the first trimester by taking a detailed medical history and asking women about risk factors.

In the second and third trimesters, urine is tested for high amounts of protein, a possible sign of preeclampsia. Although protein in the urine (proteinuria) was once considered a diagnostic sign of preeclampsia, not all women with preeclampsia will have proteinuria. During routine prenatal exams, your healthcare practitioner will also look for other signs and symptoms of preeclampsia, including high blood pressure, hand and face swelling, and sudden weight gain, persistent or severe headaches and/or changes in vision.

If you have signs or symptoms of preeclampsia, your healthcare practitioner will order additional laboratory and imaging tests to diagnose preeclampsia and determine its severity.

Laboratory Tests

The following tests may be ordered help to diagnose preeclampsia, determine its severity and cause, and monitor its progression:

If your healthcare practitioner suspects you may have HELLP syndrome, the following tests may be done:

  • Peripheral blood smear – red blood cells are examined with a microscope for damage or abnormalities.
  • Lactate dehydrogenase (LD) – elevated LD levels indicate tissue or cell damage, which occurs in the breakdown of red blood cells.
  • Bilirubin – elevated levels of bilirubin are usually an indication of liver damage or red blood cell destruction (hemolysis).

Non-Laboratory Tests

These may include:

  • Fetal ultrasound – used to assess the baby’s health, make sure preeclampsia isn’t restricting the baby’s growth, and check for blood flow in the umbilical cord
  • Non-stress test – a non-invasive test used to monitor the baby’s health by checking the heart rate and oxygen supply

Treatment and Prevention


Treatment decisions are made based on the stage of your pregnancy and on the severity of your preeclampsia.

If you develop preeclampsia while pregnant, delivering your baby often eliminates it. However, preeclampsia can rarely continue after delivery or can newly develop after childbirth, even if you didn’t show signs and symptoms during pregnancy. (See below for treatment of postpartum preeclampsia).

When preeclampsia occurs during pregnancy, your healthcare provider will decide when to deliver your baby. The goal is to try to minimize your risk from preeclampsia while allowing your baby the maximum time to grow and develop.

  • If your pregnancy is far enough along (usually at least 37 weeks), your healthcare provider may recommend delivery to reduce the risk of your condition progressing to eclampsia. You may be given medication to induce labor or you may need to undergo a Cesarean section (C-section).
  • If it is too early to deliver your baby and your signs and symptoms are not severe, you may be able to manage your preeclampsia at home. In this case, your healthcare provider will monitor you closely with weekly or sometimes twice weekly checkups. You may be asked to monitor your blood pressure while at home and track your baby’s movements (e.g., counting how often the baby kicks each day).
  • If you are hospitalized for preeclampsia, you and your baby will be closely monitored. You may be given medicine to lower your blood pressure (antihypertensives) and to prevent seizures (anticonvulsants, such as magnesium sulfate). If your pregnancy is at less than 34 weeks, you may be given corticosteroids to temporarily improve liver and platelet function and help prolong your pregnancy. Corticosteroids can also help to speed up your baby’s lung development since an early delivery is more likely. If you or your baby’s condition worsens, then prompt delivery is required.

Postpartum preeclampsia is typically treated with medications.

  • If your blood pressure is dangerously high, you may be given medication to lower it.
  • If your other signs and symptoms are severe, you may be given mediation to prevent seizures (e.g., magnesium sulfate).
  • You may be given blood-thinners (anticoagulants) to prevent blood clots from forming.


It is never too early to prepare for pregnancy. Talking with a healthcare professional about personal health history, medications, lifestyle changes, and potential risks for both mother and baby before getting pregnant is ideal. While many risk factors for preeclampsia cannot be controlled, there are some things you can do to reduce your risk. When planning a pregnancy and before becoming pregnant:

  • Ensure that pre-existing conditions such as high blood pressure or diabetes are well managed.
  • Lose weight if you are overweight or obese.

The U.S. Preventive Services Task Force recommends that pregnant women with risk factors for preeclampsia (e.g., preeclampsia with a prior pregnancy, chronic high blood pressure, kidney disease, diabetes, autoimmune disease) and no history of adverse reactions to aspirin take a low dose of aspirin (81 mg) as preventive medication each day after the 12th week of pregnancy. (As of September 2020, this recommendation is under review.)

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