What are preeclampsia and eclampsia?
Preeclampsia and eclampsia are part of the spectrum of high blood pressure, or hypertensive, disorders that can occur during pregnancy. At the mild end of the spectrum is gestational hypertension, which occurs when a woman who previously had normal blood pressure develops high blood pressure when she is more than 20 weeks pregnant. This problem occurs without other symptoms. Typically, gestational hypertension does not harm the mother or fetus and resolves after delivery. However, about 15% to 25% of women with gestational hypertension will go on to develop preeclampsia.
Preeclampsia is a condition that develops in women with previously normal blood pressure at 20 weeks of pregnancy or greater and includes increased blood pressure (levels greater than 140/90), increased swelling, and protein in the urine. The condition can be serious, and, if it is severe enough to affect brain function, causing seizures or coma, it is called eclampsia.
One of the serious complications of hypertensive disorders in pregnancy is HELLP syndrome, when a pregnant woman with preeclampsia or eclampsia sustains damage to the liver and blood cells. The letters in the name HELLP stand for the following problems:
- H – Hemolysis, in which oxygen-carrying red blood cells break down
- EL – Elevated Liver enzymes, showing damage to the liver
- LP – Low Platelet count, in which the cells responsible for stopping bleeding are low
What causes preeclampsia and eclampsia?
The causes of preeclampsia and eclampsia are not known. These disorders previously were believed to be caused by a toxin in the blood (referred to as toxemia), but health care providers now know that is not true.
To learn more about preeclampsia and eclampsia, scientists are investigating many factors that could contribute to the development and progression of these diseases, including:
- Placental abnormalities, such as insufficient blood flow
- Genetic factors
- Environmental exposures
- Nutritional factors
- Maternal immunology and autoimmune disorders
- Cardiovascular and inflammatory changes
- Hormonal imbalances
What are the risks of preeclampsia & eclampsia to the mother?
Risks During PregnancyPreeclampsia during pregnancy is mild in 75% of cases.1 However, a woman can progress from mild to severe preeclampsia or full eclampsia very quickly―even in a matter of days―especially if she is not treated. Both preeclampsia and eclampsia can cause serious health problems for the mother and infant.
Preeclampsia affects the placenta as well as the mother’s kidneys, liver, brain, and other organ and blood systems. The condition could lead to a separation of the placenta from the uterus (referred to as placental abruption), preterm delivery, and pregnancy loss. In some cases, preeclampsia can lead to organ failure or stroke. In severe cases, preeclampsia can develop into eclampsia, which can lead to seizures. Seizures in eclampsia cause a woman to lose consciousness, fall to the ground, and twitch uncontrollably. If not treated, these conditions can cause the death of the mother and/or the fetus.
Expecting mothers rarely die from preeclampsia in the developed world, but it is still a major cause of illness and death globally. According to the World Health Organization, preeclampsia and eclampsia cause 14% of maternal deaths each year, or about 50,000 to 75,000 women worldwide.
Risks After Pregnancy
In uncomplicated preeclampsia, the mother’s high blood pressure and increased protein in the urine usually resolve within 6 weeks of the infant’s birth. Studies, however, have shown that women who have had preeclampsia are four times more likely to develop hypertension and twice as likely to develop ischemic heart disease (reduced blood supply to the heart muscle, which can cause heart attacks), a blood clot in a vein, and stroke.
Less commonly, mothers who had preeclampsia during pregnancy could experience permanent damage to their organs. Preeclampsia could lead to kidney and liver damage or fluid in the lungs.
What are the risks of preeclampsia & eclampsia to the fetus?
Preeclampsia affects the flow of blood to the placenta. Risks to the fetus include:
- Lack of oxygen and nutrients, leading to poor fetal growth due to preeclampsia itself or if the placenta separates from the uterus before birth (placental abruption)
- Preterm birth
- Stillbirth if placental abruption leads to heavy bleeding in the mother
According to the Preeclampsia Foundation, each year, about 10,500 infants in the United States and about half a million worldwide die due to preeclampsia.1 Stillbirths are more likely to occur when the mother has a more severe form of preeclampsia, including HELLP syndrome.
Preeclampsia also can raise the risk of some long-term health issues related to preterm birth, including learning disorders, cerebral palsy, epilepsy, deafness, and blindness. Infants born preterm also risk extended hospitalization and small size. Infants who experienced poor growth in the uterus may later be at higher risk of diabetes, congestive heart failure, and hypertension.
How many women are affected by or at risk of preeclampsia
The exact number of women who develop preeclampsia is not known. Some scientists and health care providers estimate that preeclampsia affects 5% to 10% of all pregnancies globally. The rates are lower in the United States (about 3% to 5% of women), but it is estimated to account for 40% to 60% of maternal deaths in developing countries. Disorders related to high blood pressure are the second leading cause of stillbirths and early neonatal deaths in developing nations.In addition, HELLP syndrome occurs in about 10% to 20% of all women with severe preeclampsia or eclampsia.
Risk Factors for Preeclampsia
Preeclampsia occurs primarily in first pregnancies. Other factors that can increase a woman’s risk include4:
- Chronic high blood pressure or kidney disease before pregnancy
- High blood pressure or preeclampsia in an earlier pregnancy
- Women who are younger than age 20 or older than 35
- Women who are pregnant with more than one fetus
- Being African American
- Having a family history of preeclampsia
According to the World Health Organization, among women who have had preeclampsia, about 20% to 40% of their daughters and 11% to 37% of their sisters also will get the disorder.
Preeclampsia is more common among women who have histories of certain health conditions, such as migraine headaches, diabetes, rheumatoid arthritis, lupus, scleroderma, urinary tract infection, gum disease, polycystic ovary syndrome, multiple sclerosis, gestational diabetes, and sickle cell disease.
Preeclampsia is also more common in pregnancies resulting from egg donation, donor insemination, or in vitro fertilization.
What are the symptoms of preeclampsia, eclampsia, & HELLP syndrome?
Possible symptoms of preeclampsia include:
- High blood pressure
- Too much protein in the urine
- Swelling in a woman’s face and hands (a woman’s feet might swell too, but swollen feet are common during pregnancy and may not signal a problem)
- Systemic problems, such as headache, blurred vision, and right upper quadrant abdominal pain
Women with preeclampsia can develop seizures. The following symptoms are cause for immediate concern:
- Severe headache
- Vision problems, such as temporary blindness
- Abdominal pain, especially in the upper right area of the belly
- Nausea and vomiting
- Smaller urine output or not urinating very often
HELLP syndrome can lead to serious complications, including liver failure and death.1
A pregnant woman with HELLP syndrome might bleed or bruise easily and/or experience abdominal pain, nausea or vomiting, headache, or extreme fatigue. Although most women who develop HELLP syndrome already have high blood pressure and preeclampsia, sometimes the syndrome is the first sign. In addition, HELLP syndrome can occur without a woman having either high blood pressure or protein in her urine.
How do health care providers diagnose preeclampsia, eclampsia, and HELLP syndrome
A health care provider should check a pregnant woman’s blood pressure and urine during each prenatal visit. If the blood pressure reading is considered high (140/90 or higher), especially after the 20th week of pregnancy, the health care provider will likely perform more extensive lab tests to look for extra protein in the urine (called proteinuria) as well as other abnormalities.
Gestational hypertension is diagnosed if the woman has high blood pressure but no protein in the urine. Gestational hypertension occurs when women with normal blood pressure levels before pregnancy develop high blood pressure after 20 weeks of pregnancy. Gestational hypertension can develop into preeclampsia.1
Mild preeclampsia is diagnosed when a pregnant woman has:
- Systolic blood pressure (top number) of 140 mmHg or higher or diastolic blood pressure (bottom number) of 90 mmHg or higher
- Urine with 0.3 or more grams of protein in a 24-hour specimen (a collection of every drop of urine within 24 hours)
Severe preeclampsia occurs when a pregnant woman has:
- Systolic blood pressure of 160 mmHg or higher or diastolic blood pressure of 110 mmHg or higher on two occasions at least 6 hours apart
- Urine with 5 or more grams of protein in a 24-hour specimen or 3 or more grams of protein on 2 random urine samples collected at least 4 hours apart
- Test results suggesting blood or liver damage—for example, blood tests that reveal low numbers of red blood cells, low numbers of platelets, or high liver enzymes
- Symptoms that include severe weight gain, difficulty breathing, or fluid buildup2
Eclampsia occurs when women with preeclampsia develop seizures.
A health care provider may do other tests to assess the health of the mother and fetus, including:
- Blood tests to see how well the mother’s liver and kidneys are working
- Blood tests to check blood platelet levels to see how well the mother’s blood is clotting
- Blood tests to count the total number of red blood cells in the mother’s blood
- A maternal weight check
- An ultrasound to assess the fetus’s size
- A check of the fetus’s heart rate
- A physical exam to look for swelling in the mother’s face, hands, or legs as well as abdominal tenderness or an enlarged liver
HELLP syndrome is diagnosed when laboratory tests show hemolysis, elevated liver enzymes, and low platelets. There also may or may not be extra protein in the urine.3
What are the treatments for preeclampsia, eclampsia, & HELLP syndrome
The only cure for preeclampsia when it occurs during pregnancy is delivering the fetus. Treatment decisions need to take into account the severity of the condition and the potential for maternal complications, how far along the pregnancy is, and the potential risks to the fetus. Ideally, the health care provider will minimize risks to the mother while giving the fetus as much time as possible to mature before delivery.
If the fetus is at 37 weeks or later, the health care provider will usually want to deliver it to avoid further complications.
If the fetus is younger than 37 weeks, however, the woman and her health care provider may want to consider other options that give the fetus more time to develop, depending on how severe the condition is. A health care provider may consider the following treatment options:
- If the preeclampsia is mild, it may be possible to wait to deliver the infant. To help prevent further complications, the health care provider may ask the woman to go on bed rest (to try to lower blood pressure and increase the blood flow to the placenta).
- Close monitoring of the woman and her fetus will be needed. Tests for the mother might include blood and urine tests to see f the preeclampsia is progressing (such as tests to assess platelet counts, liver enzymes, kidney function, and urinary protein levels). Tests for the fetus might include ultrasound, heart rate monitoring, assessment of fetal growth, and amniotic fluid assessment.
- Anticonvulsive medication, such as magnesium sulfate, might be used to prevent a seizure.
- In some cases, such as with severe preeclampsia, the woman will be admitted to the hospital so she can be monitored closely. Treatment in the hospital might include intravenous medication to control blood pressure and prevent seizures or other complications as well as steroid injections to help speed up the development of the fetus’s lungs.
When a woman has severe preeclampsia, the doctor will probably want to deliver the fetus as soon as possible. Delivery usually is suggested if the pregnancy has lasted more than 34 weeks. If the fetus is less than 34 weeks, the doctor will probably prescribe corticosteroids to help speed up the maturation of the lungs.1
In some cases, the doctor must deliver the fetus prematurely, even if that means likely complications for the infant because of the risk of severe maternal complications The symptoms of preeclampsia usually go away within 6 weeks of delivery.2
Eclampsia—the onset of seizures in a woman with preeclampsia—is considered a medical emergency. Immediate treatment, usually in a hospital, is needed to stop the mother’s seizures; treat blood pressure levels that are too high; and deliver the infant.
Magnesium sulfate (a type of mineral) may be given to treat active seizures and prevent future seizures. Antihypertensive medications may be given to lower the blood pressure.
The only cure for gestational eclampsia is to deliver the fetus.
HELLP syndrome, a special type of severe preeclampsia, can lead to serious complications for the mother, including liver failure and death, as well as the fetus. The health care provider may consider the following treatments after a diagnosis of HELLP syndrome:
- Delivery, particularly if the pregnancy is 34 weeks or later
- Hospitalization to provide intravenous medication to control blood pressure and prevent seizures or other complications as well as steroid injections to help speed up the development of the fetus’s lungs.