Also known as toxemia or pregnancy-induced hypertension (PIH), preeclampsia is a common complication of pregnancy. It is characterized by high blood pressure and excessive levels of protein in the urine. Some patients experience symptoms, such as swelling, severe headache, blurred vision and right-sided upper abdominal pain.

Preeclampsia is one of several blood pressure disorders that can occur during pregnancy. Typically developing after the 20^th week of pregnancy, it can lead to many complications for the expectant mother and her fetus. Left untreated, the condition may escalate to HELLP (a syndrome characterized by hemolysis, elevated liver enzyme levels and a low platelet count) or eclampsia (preeclampsia with seizures), two potentially fatal conditions. Potential complications from preeclampsia for the fetus include premature birth and intrauterine growth retardation.

Because the complications of preeclampsia can be so severe, early detection and early treatment are essential for the health of the patient and her fetus. However, the signs and symptoms often go unnoticed by the patient. As a result, the condition is often discovered during routine prenatal blood pressure checks and urine tests.

The exact cause of the condition is unknown but common theories include calcium deficiency, high body fat and poor nutrition. The Preeclampsia Foundation estimates that preeclampsia affects at least 5 to 8 percent of all pregnancies. Certain factors can increase this risk, including having a personal history of the condition. Preeclampsia is more common among pregnant women under age 18 or over age 40. There are no known prevention methods for this condition.

Delivery is the only cure for preeclampsia. When vaginal delivery may be too stressful for the expectant mother or her fetus, a Caesarean section may be performed. In some cases, the fetus may not be developed enough to survive outside the uterus, or the cervix may not be ready for vaginal delivery. In these cases, physicians may choose to treat the symptoms with bedrest and medication until the fetus has matured. For severe cases of preeclampsia, the fetus may be removed without regard to its development or the readiness of the cervix.

Preeclampsia is a condition characterized by the development of elevated blood pressure, swelling and proteinuria (protein in the urine) during pregnancy. A common complication of pregnancy, the condition affects the expectant mother and her fetus.

Also known as toxemia or pregnancy-induced hypertension (PIH), preeclampsia is a condition that occurs only during pregnancy and the postpartum period. Although it may occur at any time during pregnancy, delivery and up to six weeks postpartum, it most often occurs after the 20^th week of pregnancy.

Blood pressure is the measure of the force of the blood pushing against the walls of the arteries (the blood vessels that carry blood from the heart to the rest of the body). The higher the measurement, the higher the workload and strain on the heart. Blood pressure is measured by correlating it to the rhythmic contractions of the heart. Blood pressure measured during the heart’s contraction phase (systole) is known as systolic pressure. Blood pressure measured during the heart’s relaxation phase (diastole) is known as diastolic pressure. The measurements are then expressed as a ratio of systolic pressure over diastolic pressure.

According to the American Heart Association, a blood pressure reading less than 120/80 millimeters of mercury (mm Hg) is considered normal. For pregnant women, blood pressure readings below 130/85 mm Hg are considered normal. A reading of 140/90 mm Hg or higher is considered high, or above the normal range. Obstetrician-gynecologists (ObGyns) usually monitor blood pressure closely during pregnancy because high blood pressure (hypertension) can develop rapidly, especially during the last three months.

Preeclampsia does not appear to cause chronic high blood pressure. It is usually resolved within 48 hours of delivery. In some cases, it may take a few days or weeks for blood pressure to return to normal.

In addition to high blood pressure, women with preeclampsia also develop proteinuria (the presence of abnormally high levels of protein in the urine).

By itself, high blood pressure is not preeclampsia. In addition, proteinuria alone does not necessarily indicate preeclampsia. However, when a woman develops high blood pressure her ObGyn will closely monitor her for changes that could indicate preeclampsia.  

Patients may also have edema (swelling caused by the buildup of fluid in the tissues). Although some degree of swelling is normal during pregnancy, the swelling associated with preeclampsia is more severe.

Swelling during pregnancy should be considered a concern if it does not decrease after resting, if it is very noticeable in the face or hands, or if there is a rapid weight gain of more than 5 pounds in a week.

According to the Preeclampsia Foundation, preeclampsia affects at least 5 to 8 percent of all pregnancies. It may develop gradually or occur suddenly, possibly flaring up in a matter of hours. Most women with preeclampsia deliver healthy babies but the condition can cause serious complications for the mother and her fetus. Preeclampsia may be described as mild or severe. In general, the more serious a woman’s preeclampsia and the earlier it occurs, the greater the risk of complications.

Left untreated, preeclampsia can progress into two serious conditions:

• HELLP syndrome. HELLP stands for:
  
  
• Hemolysis (the destruction of red blood cells)
• Elevated liver enzymes
• Low platelet count
  
  
According to the Preeclampsia Foundation, HELLP syndrome occurs in 4 to 12 percent of women with preeclampsia. It can lead to liver failure and coagulation (blood clotting) disorders, and poses a high risk of death for the mother and her fetus. It is especially dangerous because it can occur before the expectant mother exhibits any sign or symptom of preeclampsia. The condition is frequently mistaken for influenza or gallbladder disorders.


• Eclampsia. This rare condition is characterized by seizures caused by preeclampsia. It can develop when the signs and symptoms of preeclampsia are not controlled. A life-threatening condition, eclampsia can cause permanent damage to the expectant mother’s vital organs including the brain, liver and kidneys. Left untreated, the condition can lead to coma, brain damage or death of the mother or her fetus.

Preeclampsia was given its name because it was first defined as the condition that led to eclampsia. However, physicians now realize that the progression from one condition to the other is not inevitable.

The elevation in blood pressure increases the expectant mother’s risk of numerous other conditions including stroke and pulmonary edema (fluid in the lungs). Women who experience high blood pressure during pregnancy also appear to be at greater risk of stroke, heart and kidney disease later in life, according to new findings.

Preeclampsia also increases the risk of a rare condition called placental abruption (the placenta separating from the inner wall of the uterus before delivery, also called placental abruptio). Severe placental abruption can lead to heavy bleeding, which can cause the mother to go into shock. Like eclampsia, placental abruption is life-threatening for the mother and her fetus.

Potential complications for the fetus include:

• Premature birth. Reduced blood flow to the placenta may cause the birth of a baby weighing less than 5.5 pounds (2.5 kilograms). Infants being born prematurely as the result of preeclampsia may face a variety of life challenges, including learning disabilities, cerebral palsy, epilepsy, blindness and deafness.
  
  
• Intrauterine growth retardation. Reduced blood flow to the placenta decreases the supply of food to the baby, possibly resulting in starvation. As a result, the fetus may experience a decreased rate of growth and development.
  
  
• Acidosis. Reduced blood flow to the placenta results in less oxygen reaching the fetus. If the fetus comes to a point where there is no further reserve of oxygen (the placenta detaches or dies), the fetus will extract the energy it needs from its fuel supply without oxygen. This process produces lactic acid, a toxic waste product. If excessive lactic acid builds up, the fetus will develop acidosis and become unconscious.

Although preeclampsia may lead to the development of many complications, it is usually detected early during routine prenatal visits. As a result, most problems can be prevented. According to the National Institutes of Health (NIH), preeclampsia rarely causes maternal death in the United States. However, the rate of fetal and perinatal death is high. According to the Preeclampsia Foundation, more than 1,200 babies die as the result of preeclampsia each year in the United States. This rate generally decreases as the fetus matures in the womb. Worldwide, approximately 76,000 maternal and fetal deaths are caused by preeclampsia every year.

In addition to preeclampsia, three other blood pressure disorders can occur in pregnancy:

• Gestational hypertension. Pregnant women with this condition have high blood pressure (hypertension) but no excess protein in their urine (proteinuria). In most cases, the blood pressure is only mildly elevated and occurs in the later stages of pregnancy. Women diagnosed with gestational hypertension will be monitored for proteinuria, which suggests that the condition has progressed into preeclampsia. According to the Mayo Clinic, approximately one in four women with gestational hypertension develops preeclampsia. This condition is also known as transient hypertension.
  
  
• Chronic hypertension. Pregnant women with this condition have high blood pressure that appears before the 20th week of pregnancy or lasts more than 12 weeks after delivery. Although some women are aware of their high blood pressure before becoming pregnant, many women are unaware of the disorder. Chronic hypertension is often discovered during prenatal care. However, because blood pressure is often low in early pregnancy, it may not be detected immediately. Because this condition is not caused by pregnancy, it does not disappear after delivery. For women who have high blood pressure before becoming pregnant, pregnancy can make the condition more severe.  Women with preexisting high blood pressure will require close monitoring to ensure a normal pregnancy and a healthy baby.
  
  
• Preeclampsia superimposed on chronic hypertension. Pregnant women with this condition have chronic high blood pressure before they become pregnant and develop proteinuria following pregnancy. The term also describes women who have high blood pressure and proteinuria before pregnancy, when either of the conditions worsens during the last half of the pregnancy.

The exact cause of preeclampsia is unknown. However, there are numerous theories about the condition’s cause. Theoretical causes include:

• Uterine ischemia/underperfusion. Inadequate blood flow to the uterus.
  
  
• Prostacyclin/thromboxane imbalance. A disruption in the balance of hormones that control the diameter of the blood vessels.
  
  
• Endothelial activation and dysfunction. Damage to the lining of the blood vessels that controls the diameter of the blood vessels (keeping fluid and protein inside the blood vessels) and prevents blood from clotting.
  
  
• Calcium deficiency. A lack of calcium, a substance that helps maintain vasodilation (widening of the blood vessels).
  
  
• Immunological activation. The immune system mistakenly tries to fix damage to a blood vessel that has not occurred, causing actual injury.
  
  
• Hemodynamic vascular injury. Blood vessel injury caused by too much blood flow.
  
  
• Preexisting maternal conditions (e.g., diabetes, lupus, sickle cell disorder, hyperthyroidism, kidney disorder, undiagnosed high blood pressure).
  
  
• Poor diet (e.g., not enough protein, excessive protein, not enough antioxidants).
  
  
• High body fat.
  
  
• Insufficient magnesium oxide and vitamin B6.
  
  
• Genetic tendency.

Although none of these theories have been proven, researchers have identified a number of factors that make a woman more likely to develop the condition. Risk factors for preeclampsia include:

• Personal medical history. Women who have had preeclampsia during a prior pregnancy have an increased risk of developing the condition in later pregnancies. According to the National Institutes of Health (NIH), the risk of recurrent preeclampsia in later pregnancies is approximately 33 percent. Women with a personal history of preeclampsia are encouraged to discuss subsequent pregnancies with their physicians, in order to discuss the possible risks and weigh the potential options. 
  
  
• Family history. Women with a first degree relative (e.g., mother, sister) who had preeclampsia are more likely to develop the condition.
  
  
• First pregnancy. There is an increased risk of developing the condition in a woman’s first pregnancy (excluding miscarriages). The risk is also increased in a woman’s first pregnancy with a new partner or first pregnancy in 10 years or more.
  
  
• Age. Women under age 18 and over age 40 at the time of pregnancy are more likely to develop the condition.
  
  
• Obesity. Women with a pre-pregnancy body mass index (BMI) greater than 30 are at an increased risk of developing the condition.
  
  
• Multiple pregnancy. Women carrying two or more babies are more likely to develop preeclampsia.
  
  
• History of certain conditions. Having certain conditions before pregnancy can increase a woman’s risk of developing preeclampsia. These conditions include chronic high blood pressure, diabetes, kidney disease, polycystic ovarian syndrome, sarcoidosis, multiple sclerosis and connective tissue disease (e.g., rheumatoid arthritis, lupus).
  
  
• Race. African-American women are more likely to develop the condition.

The most common indicators of preeclampsia are:

• High blood pressure (hypertension). A blood pressure measurement of 140/90 millimeters of mercury (mm Hg) or greater as measured on two separate occasions within six hours. Women who normally have a low baseline blood pressure, such as 90/60, could be considered hypertensive at a blood pressure of less than that, especially when other symptoms are present. 
  
  
• Proteinuria (protein in the urine). A basic dipstick test conducted in a urine sample at each prenatal visit can screen for proteinuria.
  
  
• Edema (excessive swelling due to the buildup of fluid in the tissues). Although swelling is common during pregnancy, extreme swelling of the feet, ankles, hands and face is a cause for concern.

Other common signs and symptoms of preeclampsia include:

• Sudden weight gain. A gain of more than 2 pounds in a week or 6 pounds in a month.
  
  
• Severe headaches. Dull, throbbing, migraine-like headaches.
  
  
• Nausea or vomiting.
  
  
• Dizziness.
  
  
• Changes in vision. Preeclampsia may cause a temporary loss of vision, sensations of flashing lights, light sensitivity, blurry vision or spots. In women who are farsighted, vision may improve.
  
  
• Rapid pulse.
  
  
• Mental confusion.
  
  
• Unexplained anxiety.
  
  
• Shortness of breath.
  
  
• Decreased urine output (less than a pint in 24 hours).
  
  
• Pain in the upper right abdomen.
  
  
• Lower back pain. Although back pain is common during pregnancy, it may indicate liver abnormalities.

Additional symptoms of preeclampsia include:

• Fatigue
• Decreased fetal activity
• Bruising easily
• Agitation
• Vomiting blood
• Vaginal bleeding or blood in the urine
• Ringing or buzzing sounds in ears
• Fever
• Hyperreflexia (overactive reflexes)

Pregnant women experiencing any of these symptoms should immediately contact their obstetrician-gynecologist (ObGyn). This will allow for early detection and treatment of the condition. However, in many cases women with preeclampsia do not feel ill. This may be linked to the fact that many symptoms of preeclampsia mimic the normal effects of pregnancy on the body. It is also common for women with rapidly progressing preeclampsia to report only a few symptoms. For this reason, it is important for women to keep all prenatal appointments for physician monitoring.

Preeclampsia is diagnosed largely from its symptoms. However, symptoms are not always apparent. The disorder is usually discovered during routine prenatal blood pressure checks and urine tests. As a result, regular prenatal care throughout a pregnancy is important for the diagnosis of preeclampsia.

High blood pressure (hypertension) is one of the primary signs of preeclampsia. Typically, blood pressure is measured by wrapping an arm cuff (attached to a monitor) snugly around the patient’s arm and then using a stethoscope to listen to the brachial artery located at the inside elbow on the same arm. The cuff is pumped full of air until circulation is briefly cut off. Then some air will be slowly let out of the device, loosening the cuff’s grip on the arm and allowing the blood to flow freely again. As the air is let out, the examiner watches the numbers coming down on a simple monitor (sphygmomanometer) and waits until first hearing the heartbeat. The number at which that occurs is the systolic pressure. The examiner remembers this as the numbers continue to come down on the monitor and notes the number at which the heartbeat is last heard. The number at which that occurs is the diastolic pressure.

However, a high blood pressure measurement is not enough to diagnose preeclampsia. A reading above the normal range, or a reading that is significantly higher than a woman’s normal blood pressure, will require close monitoring. The patient may be asked to visit the physician’s office for additional blood pressure checks and urine tests at least once a week and possibly more often.

The urine tests will be used to detect protein in the urine, another major sign of preeclampsia. For this test, a sample of the patient’s urine is collected. A chemically coated dipstick is then inserted into the urine to measure the amount of protein in the sample. Additionally, the patient may be asked to collect all of her urine over a 24 hour period of time to measure the total amount of protein in this specimen. When the patient has high blood pressure and proteinuria, blood tests may be ordered to verify the diagnosis.

The blood tests may focus on measuring the amount of platelets in the patient’s blood. Thrombocytopenia (a platelet count less than 100,000) is a sign of preeclampsia.

The obstetrician-gynecologist (ObGyn) may also order blood tests to detect hemolysis (destruction of red blood cells), and to determine if the liver is functioning normally. Elevated liver function test results and hemolysis are signs of the condition.

In addition, the physician may recommend using ultrasound (a device that uses sound waves to produce an image of the uterus) to monitor the fetus’ growth. The patient may also require a nonstress test (NST) or biophysical profile. These tests can be used to determine if the fetus is getting enough oxygen and nourishment. An NST is a non-invasive test that measures how often the fetus moves and how much its heart rate increases with each movement. A biophysical profile is a test that combines an ultrasound with an NST to reveal information about the fetus’s breathing, movement and tone. It also provides information about the amount of amniotic fluid in the mother’s uterus.   

Delivery is the only cure for preeclampsia. A woman’s blood pressure usually returns to normal within a few days of delivery. However, delivery is not always a safe option. Delivering a baby too early in the pregnancy may be harmful to the baby. As a result, an obstetrician-gynecologist (ObGyns) will always consider the extent of a baby’s development before inducing labor to treat preeclampsia.

In general, physicians will wait to induce labor until after the expectant mother reaches 36 weeks of pregnancy. For the safety of the baby and the expectant mother, a physician will typically not allow a pregnancy complicated with preeclampsia to continue past 40 weeks. The readiness of the cervix is another factor considered before labor is induced. 

When waiting is necessary, there are several methods that may be recommended to manage the preeclampsia, while giving the baby additional time to develop. These methods include:

• Bed rest. Bedrest may be used to increase blood flow to the placenta and lower the expectant mother’s blood pressure. The rules of bedrest vary for each situation. For mild preeclampsia, women may be required to continuously lie in bed, sitting up and standing only when necessary. Other women may be able to sit on the couch or bed, while limiting their activities. Patients on bedrest may be required to visit their ObGyn a few times a week for blood pressure monitoring, urine tests and an evaluation of the baby’s health status. 
  
  For more severe cases of preeclampsia, bedrest in a hospital may be necessary. During her hospitalization, the expectant mother may undergo frequent nonstress tests or biophysical profiles to monitor the baby’s health. Ultrasound exams may also be used to measure the amount of amniotic fluid. A low level of amniotic fluid may be a sign of insufficient blood flow to the baby, and inducing labor may be recommended. 
  
  
• Medications. Although they cannot cure the condition, medications may be used to treat the signs and symptoms of preeclampsia. Antihypertensives, such as beta blockers, may be used to lower blood pressure levels in women who experience hazardous increases in blood pressure. For women with severe preeclampsia, corticosteroids may be used to temporarily improve liver and platelet functioning. Corticosteroids can also help the baby’s lungs develop. Magnesium sulfate also can be given intravenously to prevent the seizures associated with eclampsia.

Women may also be asked to lie on their left side as much as possible. This takes the weight of the baby off the major blood vessels of the body, improving blood flow. Drinking eight glasses of water a day and reducing salt intake may also be recommended. However, a pregnant woman’s body needs a certain amount of salt to maintain the flow of fluid in the body. A woman should ask her physician for a recommendation of how much salt is healthy to consume each day.

In very severe cases of preeclampsia, waiting for the baby to develop or the cervix to prepare may not be possible. It may be too risky to wait when the mother develops:

• Diastolic blood pressure that is consistently higher than 100 mm Hg for a 24-hour period. This is a risk factor for stroke.
  
  
• A confirmed diastolic blood pressure reading over 110 mm Hg. This is a risk factor for stroke.
  
  
• Constant and severe headaches. This is a risk factor for seizures.
  
  
• Abnormal liver function tests. This is a risk factor for liver rupture.
  
  
• Persistent abdominal pain. This is a risk factor for liver rupture.
  
  
• Rising serum creatinine levels. This is a risk factor for kidney failure.
  
  
• HELLP syndrome. This is a risk factor for liver failure, coagulation (blood clotting) disorders, and death.
  
  
• Pulmonary edema (fluid and swelling in the lungs). This is a sign of a weakening heart.
  
  
• Eclampsia. This is a risk factor for organ damage, coma, brain damage and death.
  
  
• Thrombocytopenia (a platelet count less than 100,000). This is a risk factor for severe bleeding.
  
  
• Severely decreased urine output. This is a risk factor for kidney failure.

Certain findings during fetal monitoring are also considered reasonable factors for early delivery, including:

• Non-reassuring findings during fetal monitoring (as noted by ultrasound or nonstress test)
  
  
• Failure of fetal growth (as noted by ultrasound)
  
  
• Abnormal biophysical profile
  
  
• Decreased blood flow through the umbilical cord (as noted on Doppler ultrasound tests)
  
  
• Decreased amount of amniotic fluid (as noted on ultrasound)

According to the National Institutes of Health (NIH), prolonging pregnancies in which these conditions have developed commonly result in maternal complications, as well as infant death in about 87 percent of cases. In these situations, a physician may induce labor or perform a Caesarean section before the 36^th week of pregnancy. However, for pregnancies less than 24 weeks the probability of a viable fetus is minimal.

During labor and delivery, the expectant mother may be given magnesium sulfate intravenously to improve blood flow to the uterus and prevent seizures (eclampsia). Magnesium sulfate is usually continued for 24 hours after delivery. A C-section may be chosen over vaginal delivery when either the expectant mother or the fetus may be unable to tolerate labor.

The symptoms of preeclampsia usually disappear within three to seven days of delivery. If the condition lasts beyond this period, it will require long-term treatment, as with other forms of hypertension.

There are no proven ways to avoid preeclampsia, but obesity is a controllable risk factor. Women who may benefit from reducing their body weight before pregnancy should discuss with their physician ways of lowering their risk, including exercise and diet.

Health experts generally recommend for women to make efforts to protect or improve their health prior to becoming pregnant, which in turn may help prevent some complications during pregnancy. Women who plan their pregnancies tend to take care of themselves as though they were pregnant. Planning a pregnancy also allows women to treat or control any conditions (e.g., obesity, diabetes, seizures, high blood pressure, thyroid disorders) that may threaten the health of the fetus’ before their pregnancy.

In addition, women who regularly take multivitamins three months prior to conception and during the first trimester of pregnancy may reduce the risk of developing preeclampsia, according to a new study.

Physicians and researchers are continuing to study the possible benefits of exercise, good nutrition, low-dose aspirin, calcium and antioxidants. Although some obstetrician-gynecologists (ObGyns) recommend low doses of aspirin and increasing calcium intake, more research is necessary to verify the preventive benefits of these and all other prevention methods. Most recently, two separate studies found no evidence that taking large doses of the antioxidant vitamins C and E during pregnancy helps prevent preeclampsia. 

Pregnant women may benefit the most from obtaining early and continuing prenatal care. Regular prenatal care allows for early diagnosis and treatment of preeclampsia.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about preeclampsia: 

1. Am I at risk for preeclampsia?
   
   
2. Is there anything I can do to reduce my risk for preeclampsia?
   
   
3. What tests will be done to diagnose preeclampsia?
   
   
4. How will the condition be monitored during my pregnancy?
   
   
5. What are the chances that my preeclampsia will develop into eclampsia or HELLP?
   
   
6. What are the treatment options for my condition?
   
   
7. How will I know if my condition reaches an emergency situation?
   
   
8. Is there a chance I will be placed on total bedrest with preeclampsia?
   
   
9. Will I likely need a C-section if I develop preeclampsia?
   
   
10. How will the condition affect a vaginal delivery?
    
    
11. Will I continue to have high blood pressure after delivery?
    
    
12. What is the risk of developing preeclampsia in future pregnancies?