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Preeclampsia is a common problem during pregnancy, affecting up to one in seven pregnant women around the world. This condition is defined by high blood pressure and excess protein in the urine after 20 weeks of pregnancy. It may also be called toxemia or pregnancy-induced hypertension.

In the United States, preeclampsia (pre-e-KLAMP-se-uh) is usually mild. But, left untreated, it can lead to serious, even deadly complications for you and your unborn baby. Globally, preeclampsia and other high blood pressure disorders during pregnancy are a leading cause of maternal and infant illness and death.

The only cure for preeclampsia is delivery of your baby. After your baby is born, blood pressure usually returns to normal within a few days. So delivery is the obvious solution when preeclampsia is found near the end of your pregnancy, which is typically the case. However, if you're diagnosed earlier, treatment is trickier. You and your doctor will be faced with the delicate task of prolonging your pregnancy to allow your baby more time to mature, without putting you or your baby at risk of serious complications.

The signs of preeclampsia are elevated blood pressure (hypertension) and the presence of excess protein in your urine (proteinuria) after 20 weeks of pregnancy. Your health care provider may identify these signs of preeclampsia at one of your regular prenatal visits.

Other signs and symptoms aren't always noticeable, but you may experience:

• Severe headaches
• Changes in vision, including temporary loss of vision, blurred vision or light sensitivity
• Upper abdominal pain, usually under the ribs on the right side
• Unexplained anxiety
• Nausea or vomiting
• Dizziness
• Decreased urine output

Swelling (edema), particularly in the face and hands, was once considered a primary sign of preeclampsia. But because swelling also occurs in a large number of normal pregnancies, it's no longer considered a reliable indicator. However, sudden weight gain — typically more than two pounds a week or six pounds a month — may be an early sign of preeclampsia.

Preeclampsia can develop gradually or come on suddenly. It may occur during the last half of pregnancy, during delivery or even in the first few days after your baby is born. But it's most common in the last few weeks of pregnancy and usually resolves soon after delivery. In some cases, it takes a few days or weeks for blood pressure to completely return to normal.

Other high blood pressure disorders during pregnancy
Doctors classify preeclampsia as one of four high blood pressure disorders that can occur during pregnancy. The other three are:

• Gestational hypertension. Women with gestational hypertension have high blood pressure, but no excess protein in their urine. In most cases, the high blood pressure is mild and occurs in the later stages of pregnancy. If you are diagnosed with gestational hypertension, your doctor will continue checking for proteinuria, which signals that gestational hypertension has progressed into preeclampsia. About one in four women with gestational hypertension go on to develop preeclampsia.
• Chronic hypertension. Chronic hypertension is high blood pressure that appears before 20 weeks of pregnancy or lasts more than 12 weeks after delivery. In some cases, women know they have chronic high blood pressure before they become pregnant. But, in many cases, women with long-standing high blood pressure are not evaluated for the problem before they become pregnant. Their high blood pressure is discovered only during prenatal care, but because blood pressure is often low in early pregnancy, it may not be detected initially. Chronic high blood pressure isn't caused by pregnancy. If it doesn't disappear after delivery, you probably had it all along and were never diagnosed.
• Preeclampsia superimposed on chronic hypertension. This is a fancy term for women who have chronic high blood pressure before they become pregnant and then go on to develop protein in their urine. This term is also used for women who have high blood pressure and protein in the urine before pregnancy, if there is a marked increase in either problem during the last half of pregnancy.

If you are diagnosed with any of these three high blood pressure disorders, your doctor will closely monitor you and your baby. He or she will also explain possible risks and treatment options. These disorders have some similarities with preeclampsia, but they're not exactly the same.

Preeclampsia used to be called toxemia because it was thought to be caused by a toxin in a pregnant woman's bloodstream. Today, doctors and researchers know preeclampsia isn't caused by a toxin.

They've replaced this debunked theory with lots of other theories about what may cause preeclampsia, but there's no clear answer yet, despite extensive research. Possible causes include:

• Insufficient blood flow to your uterus
• Injury to your blood vessels
• Damage to the lining of your blood vessels
• A disruption in the hormones that maintain your blood vessels
• A mistake by your immune system
• Poor diet
• Lack of magnesium or calcium

The biggest risk factor for preeclampsia is simply being pregnant. Additional risk factors include:

• History of preeclampsia. A personal history of preeclampsia or family history of preeclampsia increases your risk of developing the condition.
• First pregnancy. Your chances of developing preeclampsia are greater if this is your first pregnancy, your first pregnancy with a new partner, or your first pregnancy in 10 years or more.
• Age. Your risk of preeclampsia increases if you're younger than 20 or older than 35 at the time of pregnancy.
• Obesity. Having a pre-pregnancy body mass index (BMI) greater than 30 is a risk factor for preeclampsia.
• Multiple pregnancy. Preeclampsia is more common in women who are carrying twins, triplets or more.
• History of certain conditions. Having certain conditions before you become pregnant can be a risk factor for preeclampsia. This includes chronic high blood pressure, diabetes, kidney disease or connective tissue disease — such as rheumatoid arthritis or lupus.

In a 2006 study, pregnant women who had high levels of two specific proteins in their blood were found to be more likely to develop preeclampsia than were other women. These proteins interfere with the growth and function of blood vessels. Research to confirm the findings is needed — but the discovery suggests that a blood test may one day serve as an effective screening tool for preeclampsia.

When you're pregnant, you're likely to experience some discomfort. Headaches, nausea, and aches and pains can be common. It's difficult to know when new symptoms are just part of being pregnant and when they may indicate a serious problem — especially if it's your first pregnancy. The best policy is to trust your instincts and see your health care provider if you just don't feel right.

Call your health care provider right away if you have severe headaches, blurred vision or severe pain in your abdomen. But don't take a wait-and-see approach to other ailments. Serious complications of preeclampsia can occur even before symptoms of preeclampsia, and you don't get any points for toughing it out until the situation is serious.

Preeclampsia usually shows up unexpectedly during a routine prenatal blood pressure check and urine test. So, it's important to seek regular prenatal care throughout your pregnancy.

You'll be diagnosed with preeclampsia if you have an elevated blood pressure and protein in your urine after 20 weeks of pregnancy. Normal blood pressure readings for pregnant women are below 130/85 millimeters of mercury (mm Hg). A blood pressure reading of 140/90 mm Hg or higher is considered above the normal range. However, a single high blood pressure reading doesn't mean you have preeclampsia. If you have one reading in the abnormal range — or a reading that is substantially higher than your normal blood pressure — your health care provider will closely observe your numbers. You may also be asked to come in for additional blood pressure readings and urinary protein measurements.

If you do have preeclampsia, you health care provider may want to do some blood tests to see how well your liver and kidneys are functioning and to see if your blood has the normal number of cells that help blood clot (platelets).Your health care provider may also recommend close monitoring of your baby's growth — usually using ultrasound. This test combines high-frequency sound waves and computer processing to generate pictures of the inside of your uterus.

You may need a nonstress test (NST) or biophysical profile to make sure your baby is getting enough oxygen and nourishment, especially as you approach your due date. A nonstress test is just that — a noninvasive test that causes no stress to your baby. In fact, it shouldn't be stressful for you either. The test usually takes less than 30 minutes and requires no hospitalization. It's a simple procedure that checks how often your baby moves and how much his or her heart rate increases with movement. A biophysical profile combines an ultrasound with a nonstress test to provide more information about your baby's breathing, tone, movement and the volume of amniotic fluid in your uterus.

Most women with preeclampsia go on to deliver healthy babies. But preeclampsia is a serious condition that can lead to two serious conditions and some problems for your baby. The more severe your preeclampsia and the earlier it occurs in your pregnancy, the greater the risks for you and your baby.

HELLP syndrome
HELLP syndrome is one of two serious complications of preeclampsia. HELLP stands for:

• Hemolysis — the destruction of red blood cells
• Elevated Liver Enzymes
• Low Platelet Count

Symptoms of HELLP include nausea and vomiting, headache and upper right abdominal pain. This syndrome occurs in up to 12 percent of women with preeclampsia, and it can rapidly become life-threatening. It can cause liver failure and problems with blood clotting (coagulation), which may pose a high risk of death to you or your baby. This syndrome is particularly dangerous because it can occur before you exhibit signs or symptoms of preeclampsia.

Eclampsia
The second serious complication that can develop is eclampsia — which is basically preeclampsia plus seizures. This life-threatening condition can develop when signs and symptoms of preeclampsia aren't controlled. Eclampsia can permanently damage your vital organs, including your brain, liver and kidneys. If left untreated, the condition can cause coma, brain damage and death to you or your baby.

Preeclampsia got its name because it was first identified as the condition that led to eclampsia. But now doctors realize that this progression isn't inevitable. In fact, eclampsia is rare in most countries.

The warning signs and symptoms of eclampsia include:

• Pain in the upper right side of your abdomen
• Severe headache
• Vision problems, including seeing flashing lights
• Change in mental status, such as decreased alertness

Problems for your baby
Preeclampsia affects the arteries carrying blood to your placenta. If your placenta doesn't get enough blood, your baby may receive less oxygen and nutrients. This can cause slow growth or a low birth weight. Preeclampsia is also a leading cause of preterm birth.

In addition, preeclampsia increases the risk of placental abruption — in which the placenta separates from the inner wall of the uterus before delivery. Severe abruption can cause heavy bleeding, which can cause the mother to go into shock. This condition is rare, but it's life-threatening for mother and baby. It requires immediate medical attention.

Rarely, preeclampsia may affect the fetus earlier and more severely than it affects the mother. So it's important for your doctor to monitor your unborn baby carefully even if your preeclampsia seems mild.

The only cure for preeclampsia is delivery. After delivery, blood pressure usually returns to normal within a few days. So, delivery is always beneficial for the mother, who is at increased risk of seizures, placental abruption and severe bleeding (hemorrhage) until her blood pressure goes down.

Of course, delivery may not be the best thing for your baby, if it's too early in your pregnancy. So your doctor will consider how far along your baby is in terms of development before inducing labor. Ideally, your doctor will try to manage your condition so that you can deliver your baby after you've reached 36 weeks of pregnancy. In more severe cases, it may not be possible to wait, and you may need to undergo induction or Caesarean birth earlier.

Bed rest: Buying time for baby to grow
If you aren't near the very end of your pregnancy and you have a mild case of preeclampsia, your doctor may try to delay delivery to give your baby more time to grow and mature. In this situation, your condition may be managed at home with bed rest and regular monitoring of your blood pressure.

The rules for bed rest depend on your individual situation. You may need to lie in bed, only sitting and standing when necessary. Or you may be advised to sit on the couch or in bed and to limit your activities. Bed rest can increase blood flow to your placenta and lower blood pressure in general, so it can be an effective way to give your baby extra time to mature. Your health care provider may want to see you a few times a week, to check your blood pressure, urine protein levels and the status of your baby.

A more severe case of preeclampsia often requires bed rest in a hospital. In the hospital, you'll undergo regular nonstress tests or biophysical profiles to monitor your baby's well-being. You may also have ultrasound exams to measure the volume of amniotic fluid. If the amount is too low, it's a sign that the blood supply to the baby has been inadequate, and you may need to deliver your baby.

Medications: Helpful for you and your baby
Your doctor may recommend medications to treat high blood pressure if you experience a dangerous increase in blood pressure. These medications can be lifesaving. However, lowering your blood pressure doesn't really treat the source of the problem. Delivery is still necessary to cure preeclampsia.

Corticosteroids may also be beneficial for women with preeclampsia or HELLP syndrome. Potent corticosteroid medications can temporarily improve liver and platelet functioning in women with severe preeclampsia. As a result, these medications may help prolong pregnancy in situations where the baby is too young for delivery in terms of gestational development.

Corticosteroids may serve another purpose, too. They can help make your baby's lungs more mature in as little as 48 hours. Underdeveloped lungs are one of the biggest problems facing premature infants. So corticosteroids can be an important step in helping an immature baby prepare for life outside of the uterus.

Delivery: The ultimate cure for preeclampsia
Many cases of preeclampsia are discovered at the very end of pregnancy, so they can be treated by inducing labor right away. If you have preeclampsia, your doctor probably won't let you go beyond 40 weeks of pregnancy because of the increased risks to your baby. The readiness of your cervix — whether it's beginning to open (dilate), thin (efface) and soften (ripen) — also may be a factor in determining whether or when labor will be induced.

In more severe cases, it may not be possible to consider your baby's gestational age or the readiness of your cervix. Your doctor will recommend inducing labor or performing a Caesarean birth if your health or the health of your baby is at risk or if your blood pressure continues to rise. In these cases, the benefits of delivering the baby early outweigh the risks of waiting. During delivery, you may be given magnesium sulfate intravenously to increase uterine blood flow and prevent seizures.

There's currently no known way to prevent preeclampsia. Eating less salt or changing your activities during pregnancy doesn't reduce the risk. The best way to take care of yourself — and your baby — is to seek early and regular prenatal care. If preeclampsia is detected early, you and your doctor can work together to prevent complications and make the best choices for you and your baby.

Researchers are studying the possible preventive effects of exercise, good nutrition, low-dose aspirin, calcium supplements and antioxidants. In a preliminary 2006 study, women who took multivitamins and maintained a healthy weight before conception reduced the risk of developing preeclampsia during pregnancy by more than 70 percent compared with women of a healthy weight who didn't take multivitamins or with women who took multivitamins but were overweight before conception.

Several earlier studies suggested that specific nutritional supplements could prevent preeclampsia, but these studies haven't stood the test of time. Although a healthy weight before pregnancy has clear benefits for both mother and baby, more research is needed to determine the preventive effects of multivitamins and other nutritional supplements.

Discovering that you have a condition that can affect the health of your unborn child can be downright terrifying. If you are diagnosed with preeclampsia late in your pregnancy, you may be surprised and scared by the news that you will be induced right away. If you are diagnosed earlier in your pregnancy, you may have many hours of bed rest — way too much time — to worry about the health of your baby-to-be.

You'll probably feel better if you learn as much as you can about your condition. In addition to talking to your doctor, do some research. Or ask your doctor to put you in touch with other women who have had preeclampsia.

On the other hand, if reading about preeclampsia and its possible complications is just making you more nervous and worried, find a distraction. Make sure you understand when to call your doctor, and then seek out something else to occupy your time.

Coping with bed rest
For the first few hours, bed rest may seem wonderful. You have permission to rest, and your family is waiting on you hand and foot. But the reality of life in bed, waiting and worrying, is often not so wonderful. In fact, if you don't feel sick, you may feel frustrated by this forced vacation, especially if you haven't had time to finish preparations for your baby's arrival.

Make the best of the situation by focusing on the fact that you're doing what's best for you and your baby. After all, your baby's well-being is far more important than stenciling the nursery or picking out the perfect going-home-from-the-hospital outfit.

To make bed rest tolerable, try these tips:

• Make sure you understand the ground rules. Ask your health care provider exactly what your restrictions are. What position should you use while lying down? Can you sit up at times? If so, for how long? Is there any other type of physical activity allowed?
• Prepare your resting room. Whether you choose to spend your time in your bedroom or in the living room, set up your surroundings so everything you need is within reach from the bed or couch. If you need help arranging your area, ask your partner or a family member.
• Organize your day. The hours will pass more quickly if you have some sort of routine. Schedule specific times to phone the office, watch television and read. It may help to stick to some parts of your normal schedule, such as lunchtime and lights out.
• Plan for your baby's arrival. Read about newborn care — how to bathe, dress, breast-feed and soothe your baby. Consider purchasing newborn necessities, either online or from catalogs. If you have access to a computer, you can also use the Internet to find tips and advice from other moms on bed rest.
• Keep busy. Use your time to balance the checkbook, organize old photo albums, catch up on thank-you notes or fill out health insurance paperwork for your baby in advance. Take up a new hobby, such as making a scrapbook, painting or knitting. Or learn relaxation and visualization techniques. They'll help not only during bed rest but also during labor and delivery.