What is preeclampsia

Preeclampsia is a serious high blood pressure (hypertension) and protein in the urine condition (proteinuria) that can happen after the 20th week of pregnancy or after giving birth (called postpartum preeclampsia). Preeclampsia (sometimes known as toxemia of pregnancy or pregnancy-induced hypertension) is a condition, closely related to gestational hypertension, that typically begins after the 20th week of pregnancy. Delivery of your baby is the only cure for preeclampsia ¹. But if you’re diagnosed with preeclampsia too early in your pregnancy to deliver your baby, you and your doctor face a challenging task. Your baby needs more time to mature, but you need to avoid putting yourself or your baby at risk of serious complications.

Preeclampsia is usually characterized by high blood pressure, puffiness/swollen feet and elevated protein in the urine that often occurs in first-time mothers. Delivery of the baby is the only cure for preeclampsia, except for postpartum preeclampsia. Preeclampsia is when a woman has high blood pressure and signs that some of her organs, like her kidneys and liver, may not be working normally. Blood pressure is the force of blood that pushes against the walls of your arteries. Arteries are blood vessels that carry blood away from your heart to other parts of the body. High blood pressure (also called hypertension) is when the force of blood against the walls of the blood vessels is too high. High blood pressure can stress your heart and cause problems during pregnancy. Preeclampsia can range from mild to severe in the way it presents. A very high blood pressure signifies severe disease. If severe and not treated, its complications can affect the kidneys, liver, clotting system, brain of the mother or cause growth restrictions in the fetus. If preeclampsia is severe enough to affect brain function, causing seizures or coma, it is called eclampsia. This can pose a risk to the health of the mother and baby.

• Diagnosis of preeclampsia is made when blood pressure is higher than 140/90 and significant protein in the urine.

Early-onset preeclampsia is usually more severe and often requires preterm delivery. Preterm infants (<37 weeks of gestation) are at increased risk for morbidity and mortality, and complications increase with earlier delivery. Additional important threats to the fetus from preeclampsia include intrauterine growth restriction, being small for gestational age, placental abruption, neonatal intensive care unit admission, and neonatal death. It is estimated that perinatal mortality is about 2 times higher in pregnancies affected by preeclampsia ¹. Most women with preeclampsia have healthy babies. But if it’s not treated, it can cause severe health problems for you and your baby.

Mild Preeclampsia ²

Mildly raised blood pressure after 20th week with proteinuria but no effects on the brain.

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 and either
  • Urine with 0.3 or more grams of protein in a 24-hour specimen (a collection of every drop of urine within 24 hours) or a protein-to-creatinine ratio greater than 0.3
    or
  • Blood tests that show kidney or liver dysfunction
  • Fluid in the lungs and difficulty breathing
  • Visual impairments

Outcome in mild cases is good for both mother and baby but severe disease may be associated with serious complications. Maternal deaths caused by preeclampsia are rare in Western countries. However, in less developed nations, mortality rate is considerably increased. Prognosis for the baby is dependent on the associated effects of preeclampsia on the growing fetus – low birth weight, intrauterine growth restriction (IUGR), prematurity and so on.

Moderate-Severe Preeclampsia

Highly raised blood pressure with proteinuria and effects on the brain. The effects of preeclampsia on the brain include headache, dizziness, tinnitus, altered mental status, visual changes, and seizures. The visual changes may result from spasm of the blood vessels, insufficient blood supply, and hemorrhage in the visual center of the brain, or from retinal detachment. Preeclampsia may also occur in women with pre-existing hypertension (superimposed preeclampsia), and in this situation the prognosis is poorer for mother and baby. Superimposed preeclampsia—a situation in which the woman develops preeclampsia on top of high blood pressure that was present before she got pregnant. Health care providers look for an increase in blood pressure and either protein in the urine, fluid buildup, or both for a diagnosis of superimposed preeclampsia.

Severe preeclampsia occurs when a pregnant woman has any of the following:

• Systolic blood pressure of 160 mmHg or higher or diastolic blood pressure of 110 mmHg or higher on two occasions at least 4 hours apart while the patient is on bed rest
• 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 kidney or liver damage—for example, blood tests that reveal low numbers of platelets or high liver enzymes
• Severe, unexplained stomach pain that does not respond to medication
• Symptoms that include visual disturbances, difficulty breathing, or fluid buildup ³

Eclampsia occurs when women with preeclampsia develop seizures. The seizures can happen before or during labor or after the baby is delivered.

Preeclampsia blood pressure

Preeclampsia is classified 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 or other signs of organ damage. Some women with gestational hypertension eventually develop preeclampsia.
• Chronic hypertension. Chronic hypertension is high blood pressure that was present before pregnancy or that occurs before 20 weeks of pregnancy. But because high blood pressure usually doesn’t have symptoms, it may be hard to determine when it began.
• Chronic hypertension with superimposed preeclampsia. This condition occurs in women who have been diagnosed with chronic high blood pressure before pregnancy, but then develop worsening high blood pressure and protein in the urine or other health complications during pregnancy.

Hypertension is defined as a systolic blood pressure greater than 130 mm Hg or a diastolic BP greater than 80 mm Hg.

BLOOD PRESSURE CATEGORY	SYSTOLIC mm Hg (upper number)		DIASTOLIC mm Hg (lower number)
Normal	LESS THAN 120	and	LESS THAN 80
Prehypertension	120 – 139	and	80 – 89
High Blood Pressure (Hypertension) Stage 1	140 – 159	or	90 – 99
High Blood Pressure (Hypertension) Stage 2	160 OR HIGHER	or	100 OR HIGHER
HYPERTENSIVE CRISIS (consult your doctor immediately)	HIGHER THAN 180	and/or	HIGHER THAN 120

The only way to know (diagnose) if you have hypertension (preeclampsia) is to have your blood pressure tested.

Your blood pressure reading is recorded as two numbers:

• Systolic blood pressure (the top number) — indicates how much pressure your blood is exerting against your artery walls during heartbeats (shown as the top number in a blood pressure reading).
• Diastolic blood pressure (the bottom number) — indicates how much pressure your blood is exerting against your artery walls while the heart is resting between beats (shown as the bottom number in a blood pressure reading).

If your blood pressure reading is higher than normal (120/80 mmHg):

Your doctor may take several readings over time and/or have you monitor your blood pressure at home before diagnosing you with preeclampsia.
A single high reading does not mean that you have preeclampsia. But, if your readings continue to stay high, your doctor will most likely want you to begin a treatment program.

Preeclampsia is a serious health problem for pregnant women around the world. It affects 2 to 8 percent of pregnancies worldwide (2 to 8 in 100). In 2010, preeclampsia affected 3.8% of deliveries in the United States ⁴. The rate of severe preeclampsia has increased over the past 3 decades. Of the nearly 4 million women in United States who give birth each year, experts estimate 6 percent to 10 percent of them develop preeclampsia, a dangerous spike in blood pressure that occurs late in pregnancy. Amongst women with pre-eclampsia the more serious condition, eclampsia develops in 2.3%. In the United States, preeclampsia is the cause of 15 percent (about 3 in 20) of premature births. Premature birth is birth that happens too early, before 37 weeks of pregnancy. In the United States, 12% of maternal deaths are directly attributable to preeclampsia and eclampsia.

There are racial/ethnic disparities in the prevalence of and mortality from preeclampsia. Non-Hispanic black women are at greater risk for developing preeclampsia than other women and bear a greater burden of maternal and infant morbidity and perinatal mortality. In the United States, the rate of maternal death from preeclampsia is higher in non-Hispanic black women than in non-Hispanic white women. Disparities in risk factors for preeclampsia, limited access to early prenatal care, and obstetric interventions may account for some of the differences in prevalence and clinical outcomes ¹.

Most women with preeclampsia have healthy babies. But if it’s not treated, it can cause severe health problems for you and your baby.

Without treatment, preeclampsia can cause serious health problems for you and your baby, even death. Having preeclampsia increases your risk for postpartum hemorrhage. Postpartum hemorrhage is heavy bleeding after giving birth. It’s a rare condition, but if not treated, it can lead to shock and death. Shock is when your body’s organs don’t get enough blood flow.

• You may have preeclampsia and not know it, so be sure to go to all your prenatal care checkups, even if you’re feeling fine. If you have any sign or symptom of preeclampsia, tell your healthcare provider.

Preeclampsia complications

The more severe your preeclampsia and the earlier it occurs in your pregnancy, the greater the risks for you and your baby. Preeclampsia may require induced labor and delivery.

Delivery by cesarean delivery (C-section) may be necessary if there are clinical or obstetric conditions that require a speedy delivery. Your obstetric provider will assist you in deciding what type of delivery is correct for your condition.

Health problems for women who have preeclampsia include:

• Kidney, liver, heart, lung, eyes and brain damage. Preeclampsia may result in kidney, liver, lung, heart, or eyes, and may cause a stroke or other brain injury. The amount of injury to other organs depends on the severity of preeclampsia.
• Problems with how your blood clots. A blood clot is a mass or clump of blood that forms when blood changes from a liquid to a solid. Your body normally makes blood clots to stop bleeding after a scrape or cut. Problems with blood clots can cause serious bleeding problems.
• Eclampsia. This is a rare and life-threatening condition. When preeclampsia isn’t controlled, eclampsia — which is essentially preeclampsia plus seizures — can develop. In some pregnant women a coma can develop after preeclampsia. A coma is when you’re unconscious for a long period of time and can’t respond to voices, sounds or activity. It is very difficult to predict which patients will have preeclampsia that is severe enough to result in eclampsia. Often, there are no symptoms or warning signs to predict eclampsia. Because eclampsia can have serious consequences for both mom and baby, delivery becomes necessary, regardless of how far along the pregnancy is.
• Stroke. This is when the blood supply to the brain is interrupted or reduced. Stroke can happen when a blood clot blocks a blood vessel that brings blood to the brain, or when a blood vessel in the brain bursts open.
• Cardiovascular disease. Having preeclampsia may increase your risk of future heart and blood vessel (cardiovascular) disease. The risk is even greater if you’ve had preeclampsia more than once or you’ve had a preterm delivery. To minimize this risk, after delivery try to maintain your ideal weight, eat a variety of fruits and vegetables, exercise regularly, and don’t smoke.
• HELLP syndrome. HELLP — which stands for hemolysis (the destruction of red blood cells), elevated liver enzymes and low platelet count — syndrome is a more severe form of preeclampsia, and can rapidly become life-threatening for both you and your baby. Symptoms of HELLP syndrome include nausea and vomiting, headache, and upper right abdominal pain. HELLP syndrome is particularly dangerous because it represents damage to several organ systems. On occasion, it may develop suddenly, even before high blood pressure is detected or it may develop without any symptoms at all.

Pregnancy complications from preeclampsia include:

• Premature birth. Even with treatment, you may need to give birth early to help prevent serious health problems for you and your baby. Prematurity can lead to breathing and other problems for your baby. Your health care provider will help you understand when is the ideal time for your delivery.
• Placental abruption. This is when the placenta separates from the wall of the uterus (womb) before birth. It can separate partially or completely. If you have placental abruption, your baby may not get enough oxygen and nutrients. Vaginal bleeding is the most common symptom of placental abruption after 20 weeks of pregnancy. If you have vaginal bleeding during pregnancy, tell your health care provider right away.
• Intrauterine growth restriction (also called IUGR). This is when a baby has poor growth in the womb. It can happen when mom has high blood pressure that narrows the blood vessels in the uterus and placenta. The placenta grows in the uterus and supplies your baby with food and oxygen through the umbilical cord. If your baby doesn’t get enough oxygen and nutrients in the womb, he may have intrauterine growth restriction.
• Low birthweight

Having preeclampsia increases your risk for heart disease, diabetes and kidney disease later in life. In the study, women with preeclampsia had an increased risk of left ventricular hypertrophy one month after delivery compared to pregnant women without preeclampsia. The heart problem occurs when the left pumping chamber thickens, making it more difficult for the heart to pump efficiently. The researchers also found that the heart changes were more severe in women who developed preeclampsia before the 34th week of pregnancy. None of the women in the study had high blood pressure before getting pregnant.

Preeclampsia doubles women’s stroke risk, quadruples later high blood pressure risk ⁵. Millions of women with a history of preeclampsia should be screened and treated for high blood pressure, obesity, smoking and high cholesterol to reduce their risk for stroke, according to the first-ever guidelines from the American Heart Association for preventing stroke in women.

If I have preeclampsia, can I still have a vaginal birth?

Yes. If you have preeclampsia, a vaginal birth may be better than a Cesarean birth (also called c-section). A c-section is surgery in which your baby is born through a cut that your doctor makes in your belly and uterus. With vaginal birth, there’s no stress from surgery. For most women with preeclampsia, it’s safe have an epidural to manage labor pain as long as your blood clots normally. An epidural is pain medicine you get through a tube in your lower back that helps numb your lower body during labor. It’s the most common kind of pain relief during labor.

Does preeclampsia occur in subsequent pregnancies?

This is the most common question pregnant women ask. Yes, it does and recurrence rate is estimated to vary from 5% to 25%. The American College of Obstetricians and Gynecologists Task Force on Hypertension in Pregnancy – Practice Advisory on Low-Dose Aspirin and Prevention of Preeclampsia in pregnancy recommends low-dose aspirin (81 mg/day), initiated between 12 and 28 weeks of gestation, for the prevention of preeclampsia ⁶. Moreover, the U.S. Preventive Services Task Force ⁷ and published as a clinical guideline in September 2014. In this guideline ⁷, the U.S. Preventive Services Task Force recommended the use of low-dose aspirin (81 mg/day) after 12 weeks of gestation in women at high-risk of preeclampsia. However, it’s important that you don’t take any medications, vitamins or supplements without first talking to your doctor.

Preeclampsia Risks During Pregnancy

Preeclampsia during pregnancy is mild in 75% of cases ⁸. However, a woman can progress from mild to severe preeclampsia or to full eclampsia very quickly―even in a matter of days. Both preeclampsia and eclampsia can cause serious health problems for the mother and infant.

Women with preeclampsia are at increased risk for damage to the kidneys, liver, brain, and other organ and blood systems. Preeclampsia may also affect the placenta. The condition could lead to a separation of the placenta from the uterus (referred to as placental abruption), preterm birth, and pregnancy loss or stillbirth. In some cases, preeclampsia can lead to organ failure or stroke.

In severe cases, preeclampsia can develop into eclampsia, which includes seizures. Seizures in eclampsia may cause a woman to lose consciousness and twitch uncontrollably ⁹. If the fetus is not delivered, 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 ¹⁰. 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 ¹¹.

What are the risks of preeclampsia and eclampsia to the fetus?

Preeclampsia may be related to problems with the placenta early in the pregnancy ¹². Such problems pose risks to the fetus, including:

• Lack of oxygen and nutrients, which can impair fetal growth
• Preterm birth
• Stillbirth if placental abruption (separation of the placenta from the uterine wall) leads to heavy bleeding in the mother
• Death: 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 ¹⁰.

Stillbirths are more likely to occur when the mother has a more severe form of preeclampsia, including HELLP syndrome.

Infants whose mothers had preeclampsia are also at increased risk for later problems, even if they were born at full term (39 weeks of pregnancy) ¹³. Infants born preterm due to preeclampsia face a higher risk of some long-term health issues, mostly related to being born early, including learning disorders, cerebral palsy, epilepsy, deafness, and blindness. Infants born preterm may also have to be hospitalized for a long time after birth and may be smaller than infants born full term. Infants who experienced poor growth in the uterus may later be at higher risk of diabetes, congestive heart failure, and high blood pressure ¹⁴.

Preeclampsia Risks After Pregnancy

In “uncomplicated preeclampsia,” the mother’s high blood pressure and other symptoms usually go back to normal within 6 weeks of the infant’s birth. However, studies have shown that women who had preeclampsia are four times more likely to later develop hypertension (high blood pressure) and are twice as likely to later develop ischemic heart disease (reduced blood supply to the heart muscle, which can cause heart attacks), a blood clot in a vein, and stroke as are women who did not have preeclampsia ¹⁵.

Less commonly, mothers who had preeclampsia could experience permanent damage to their organs, such as their kidneys and liver. They could also experience fluid in the lungs. In the days following birth, women with preeclampsia remain at increased risk for developing eclampsia and seizures ¹⁶.

Postpartum preeclampsia

Postpartum preeclampsia is a rare condition (5% of pregnancy). Postpartum preeclampsia is when you have preeclampsia after you’ve given birth. Postpartum preeclampsia most often happens within 48 hours (2 days) of having a baby, but it can develop up to 6 weeks after a baby’s birth. Postpartum preeclampsia is just as dangerous as preeclampsia during pregnancy and needs immediate treatment. If not treated, it can cause life-threatening problems, including death.

On average the women with postpartum preeclampsia had normal blood pressure again 5-6 weeks after delivery, however one in five women still had high blood pressure six months after their pregnancy.

Signs and symptoms of postpartum preeclampsia are like those of preeclampsia. It can be hard for you to know if you have signs and symptoms after pregnancy because you’re focused on caring for your baby. If you do have signs or symptoms, tell your healthcare provider right away.

Doctors don’t know exactly what causes postpartum preeclampsia, but these may be possible risk factors:

• You had gestational hypertension or preeclampsia during pregnancy. Gestational hypertension is high blood pressure that starts after 20 weeks of pregnancy and goes away after you give birth.
• You’re obese.
• You had a Cesarean birth.

Complications from postpartum preeclampsia include these life-threatening conditions:

• HELLP syndrome
• Postpartum eclampsia (seizures). This can cause permanent damage to our brain, liver and kidneys. It also can cause coma.
• Pulmonary edema. This is when fluid fills the lungs.
• Stroke
• Thromboembolism. This is when a blood clot travels from another part of the body and blocks a blood vessel.

HELLP stands for these blood and liver problems:

• H–Hemolysis. This is the breakdown of red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body.
• EL–Elevated liver enzymes. High levels of these chemicals can be a sign of liver problems.
• LP–Low platelet count (thrombocytopenia). Platelets help the blood clot.

HELLP syndrome is diagnosed when laboratory tests show hemolysis (burst red blood cells release hemoglobin into the blood plasma), elevated liver enzymes, and low platelets. There also may or may not be extra protein in the urine ¹⁷. HELLP syndrome occurs in about 10% to 20% of all women with severe preeclampsia or eclampsia ¹⁷.

Your provider uses blood and urine tests to diagnose postpartum preeclampsia. Treatment can include magnesium sulfate to prevent seizures and medicine to help lower your blood pressure. Medicine to prevent seizures also is called anticonvulsive medicine. If you’re breastfeeding, talk to your provider to make sure these medicines are safe for your baby.

Benschop and colleagues ¹⁸ studied 200 women who during their pregnancies were diagnosed with severe pre-eclampsia, defined by such criteria as a systolic blood pressure of 160 mmHg or higher and/or diastolic blood pressure of 110 mmHg or higher. They followed the women for one year after their pregnancies, monitoring blood pressure during the day and night and taking blood pressure readings in the clinic.

They found:

• More than 41 percent of the women in the study had high blood pressure in the year after pregnancy.
• The most common type of hypertension detected (17.5 percent) was masked hypertension, which is normal blood pressure in the doctor’s office, but high readings outside of the office; followed by sustained hypertension (14.5 percent); then, white coat hypertension (9.5 percent), which occurs when people have higher blood pressure readings at the doctor’s office than outside the clinic setting.
• If the ambulatory readings hadn’t been taken and only in-clinic readings were used, doctors would have missed 56 percent of the women with high blood pressure.
• Forty-six percent of the women studied had an insufficient decrease in blood pressure from daytime to nighttime, which is unhealthy.
• Night-time hypertension, which increases the risk of heart disease, stroke and death, affected 42.5 percent of women in the study.

Their findings suggest women who have high blood pressure during pregnancy should continue to monitor their blood pressure long after they’ve delivered their babies. It’s not only important to monitor blood pressure in the doctor’s office, but also at different times of the day and night, at home. The researchers have shown here that high blood pressure comes in many forms after pregnancy. Women who know their numbers can take the proper steps to lower their blood pressure and avoid the health consequences of high blood pressure later in life.

Preeclampsia causes

The exact cause of preeclampsia is yet to be identified. Numerous theories of possible causes include: genetic, dietary, vascular (blood vessel), and autoimmune factors. No particular factor however, has been conclusively linked to the disorder. Preeclampsia has been described as a disease originating from the placenta but with widespread effects both for the mother and baby.

Scientists still don’t know for sure what causes preeclampsia, but there are some things that may make you more likely than other women to have it. These are called risk factors. If you have even one risk factor for preeclampsia, tell your provider.

You’re at high risk for preeclampsia if:

• You’ve had preeclampsia in a previous pregnancy. The earlier in pregnancy you had preeclampsia, the higher your risk is to have it again in another pregnancy. You’re also at higher risk if you had preeclampsia along with other pregnancy complications.
• You’re pregnant with multiples (twins, triplets or more).
• You have high blood pressure, diabetes, kidney disease or an autoimmune disease like lupus or antiphospholipid syndrome. Diabetes is when you have too much sugar in the blood. This can damage organs, like blood vessels, nerves, eyes and kidneys. An autoimmune disease is a health condition that happens when antibodies (cells in the body that fight off infections) attack healthy tissue by mistake.

Other risk factors for preeclampsia include:

• You’ve never had a baby before (this is your first ever pregnancy or nulliparity), or it’s been more than 10 years since you had a baby.
• You have multifetal pregnancy (with triplets posing a greater risk than twins)
• You’re obese. Obese means being very overweight with a body mass index (also called BMI) of 30 or higher. To find out your BMI, go to https://www.cdc.gov/healthyweight/assessing/bmi/adult_BMI/english_bmi_calculator/bmi_calculator.html.
• You have type I diabetes mellitus or type II diabetes mellitus ¹⁹.
• Family history of preeclampsia. This means that other people in your family, like your sister or mother, have had it. 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 ¹¹.
• You have chronic hypertension, chronic renal disease or both.
• You have inherited disorder of blood clotting (thrombophilia), a tendency to form blood clots.
• You had complications in a previous pregnancy, like having a baby with low birthweight. Low birthweight is when your baby is born weighing less than 5 pounds, 8 ounces.
• You had a fertility treatment called in vitro fertilization (also called IVF) to help you get pregnant.
• You’re older than 35.
• New sexual partner.
• You have systemic lupus erythematosus (SLE) or antiphospholipid syndrome.
• You’re African-American. African-American women are at higher risk for preeclampsia than other women.
• You have low socioeconomic status. Socioeconomic status is a combination of things, like a person’s education level, job and income (how much money you make). A person with low socioeconomic status may have little education, may not have a job that pays well and may have little income or savings.

Preeclampsia is also more common among women who have histories of certain health conditions, such as migraines ²⁰, rheumatoid arthritis ²¹, lupus ²², scleroderma ²³, urinary tract infections ²⁴, gum disease ³, polycystic ovary syndrome ²⁵, multiple sclerosis, gestational diabetes, and sickle cell disease ¹⁰.

If your healthcare provider thinks you’re at risk of having preeclampsia, she/he may want to treat you with low-dose aspirin (81 mg/day) to help prevent it. Talk to your provider to see if treatment with low-dose aspirin is right for you.

Preeclampsia prevention

There is no proven way to prevent gestational hypertension or preeclampsia and no test that will predict or diagnose these conditions. Only regular visits to your doctor will confirm that you’re having a safe pregnancy. Your doctor will track your blood pressure and check the level of protein in your urine. For a healthy pregnancy, you should:

• Get early and regular care from your doctor. (Don’t miss appointments.)
• If advised by your doctor, monitor your blood pressure at home.
• Do what you can to help manage your blood pressure, including limiting sodium intake and getting regular physical activity.
• All women with a history of preeclampsia should be regularly evaluated and treated for cardiovascular risk factors such as high blood pressure, obesity, smoking and high cholesterol. Screening for risk factors should start within one year after delivery.
• Pregnant women with high blood pressure or who experienced high blood pressure during a previous pregnancy should talk to their healthcare providers about whether they should take low-dose aspirin starting the second trimester until delivery to lower preeclampsia risk.

Researchers continue to study ways to prevent preeclampsia, but so far, no clear strategies have emerged. Eating less salt, changing your activities, restricting calories, or consuming garlic or fish oil doesn’t reduce your risk. Increasing your intake of vitamins C and E hasn’t been shown to have a benefit.

Some studies have reported an association between vitamin D deficiency and an increased risk of preeclampsia. But while some studies have shown an association between taking vitamin D supplements and a lower risk of preeclampsia, others have failed to make the connection.

Before you become pregnant, especially if you’ve had preeclampsia before, it’s a good idea to be as healthy as you can be. Lose weight if you need to, and make sure other conditions, such as diabetes, are well-managed.

Once you’re pregnant, take care of yourself — and your baby — through 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.

In certain cases, however, you may be able to reduce your risk of preeclampsia with:

• Low-dose aspirin. If you meet certain risk factors, including a history of preeclampsia with severe features, preeclampsia resulting in a preterm delivery, chronic hypertension or a history of kidney disease, your doctor may recommend a daily low-dose aspirin — between 60 and 81 milligrams — beginning late in your first trimester.
• Calcium supplements. In some populations, women who have calcium deficiency before pregnancy — and who don’t get enough calcium during pregnancy through their diets — might benefit from calcium supplements to prevent preeclampsia. However, it’s unlikely that women from the United States or other developed countries would have calcium deficiency to the degree that calcium supplements would benefit them.

Both the U.S. Preventive Services Task Force ⁷ and the American College of Obstetricians and Gynecologists’ Task Force on Hypertension in Pregnancy ⁶ recommend women with increased risk for preeclampsia to take low-dose aspirin (81 mg/d) as preventive medication after 12 weeks of gestation (initiated between 12 and 28 weeks of gestation) in women who are at high risk for preeclampsia. Low-dose aspirin (range, 60 to 150 mg/d) reduced the risk for preeclampsia by 24% in clinical trials and reduced the risk for preterm birth by 14% and intrauterine growth restriction by 20%. Evidence did not suggest additional benefit when use of aspirin was started earlier (12 to 16 weeks) rather than later (≥16 weeks) in pregnancy in women at increased risk for preeclampsia ¹.

Women are considered to be at high-risk for preeclampsia if one or more of the following risk factors are present:

• History of preeclampsia, especially if accompanied by an adverse outcome
• Multifetal gestation
• Chronic hypertension
• Diabetes (Type 1 or Type 2)
• Renal disease
• Autoimmune disease (such as systematic lupus erythematosus, antiphospholipid syndrome)

Table 1. Clinical Risk Assessment for Preeclampsia*

Risk Level	Risk Factors	Recommendation
High†	History of preeclampsia, especially when accompanied by an adverse outcome Multifetal gestation Chronic hypertension Type 1 or 2 diabetes Renal disease Autoimmune disease (systemic lupus erythematous, antiphospholipid syndrome)	Recommend low-dose aspirin if the patient has ≥1 of these high-risk factors
Moderate‡	Nulliparity Obesity (body mass index >30 kg/m2) Family history of preeclampsia (mother or sister) Sociodemographic characteristics (African American race, low socioeconomic status) Age ≥35 years Personal history factors (e.g., low birthweight or small for gestational age, previous adverse pregnancy outcome, >10-year pregnancy interval)	Consider low-dose aspirin if the patient has several of these moderate-risk factors§
Low	Previous uncomplicated full-term delivery	Do not recommend low-dose aspirin

* Includes only risk factors that can be obtained from the patient medical history. Clinical measures, such as uterine artery Doppler ultrasonography, are not included.
† Single risk factors that are consistently associated with the greatest risk for preeclampsia. The preeclampsia incidence rate would be approximately ≥8% in a pregnant woman with ≥1 of these risk factors.
‡ A combination of multiple moderate-risk factors may be used by clinicians to identify women at high risk for preeclampsia. These risk factors are independently associated with moderate risk for preeclampsia, some more consistently than others.
§ Moderate-risk factors vary in their association with increased risk for preeclampsia.

[Source ⁷]

The U.S. Preventive Services Task Force found adequate evidence that low-dose aspirin as preventive medication does not increase the risk for placental abruption, postpartum hemorrhage, or fetal intracranial bleeding. In a meta-analysis of randomized, controlled trials and observational studies of women at low/average or increased risk for preeclampsia, there was no significantly increased risk for these adverse events. In addition, there was no difference in the risk for placental abruption by aspirin dosage.

The U.S. Preventive Services Task Force also found adequate evidence that low-dose aspirin as preventive medication in women at increased risk for preeclampsia does not increase the risk for perinatal mortality.

Evidence on long-term outcomes in offspring exposed in utero to low-dose aspirin is limited, but no developmental harms were identified by 18 months of age in the one study reviewed.

The U.S. Preventive Services Task Force concludes that the harms of low-dose aspirin in pregnancy are no greater than small.

Preeclampsia signs and symptoms

Preeclampsia sometimes develops without any symptoms. High blood pressure may develop slowly, or it may have a sudden onset. Monitoring your blood pressure is an important part of prenatal care because the first sign of preeclampsia is commonly a rise in blood pressure. Blood pressure that exceeds 140/90 millimeters of mercury (mm Hg) or greater — documented on two occasions, at least four hours apart — is abnormal.

Signs and symptoms of preeclampsia include:

• Changes in vision, like blurriness, flashing lights, seeing spots or being sensitive to light
• Severe headaches that don’t go away
• Nausea (feeling sick to your stomach), vomiting or dizziness
• Pain in the upper right belly area or in the shoulder
• Sudden weight gain (2 to 5 pounds in a week)
• Swelling in the legs, hands or face
• Shortness of breath, caused by fluid in your lungs
• Excess protein in your urine (proteinuria) or additional signs of kidney problems
• Changes in vision, including temporary loss of vision, blurred vision or light sensitivity
• Decreased urine output
• Decreased levels of platelets in your blood (thrombocytopenia)
• Impaired liver function

Many of these signs and symptoms are common discomforts of pregnancy. For example, sudden weight gain and swelling (edema) — particularly in your face and hands — may occur with preeclampsia. But these also occur in many normal pregnancies, so they’re not considered reliable signs of preeclampsia. But if you have severe headaches, blurred vision or other visual disturbance, severe pain in your abdomen, or severe shortness of breath, call your health care provider right away or go to an emergency room. Because headaches, nausea, and aches and pains are common pregnancy complaints, it’s difficult to know when new symptoms are simply part of being pregnant and when they may indicate a serious problem — especially if it’s your first pregnancy. If you’re concerned about your symptoms, contact your doctor.

Preeclampsia diagnosis

To diagnose preeclampsia, your provider measures your blood pressure and tests your urine for protein at every prenatal visit.

To be diagnosed with preeclampsia, you have to have high blood pressure and one or more of the following complications after the 20th week of pregnancy:

• Protein in your urine (proteinuria)
• A low platelet count
• Impaired liver function
• Signs of kidney trouble other than protein in the urine
• Fluid in the lungs (pulmonary edema)
• New-onset headaches or visual disturbances

A blood pressure reading in excess of 140/90 mm Hg is abnormal in pregnancy. 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’s substantially higher than your usual blood pressure — your doctor will closely observe your numbers.

Having a second abnormal blood pressure reading four hours after the first may confirm your doctor’s suspicion of preeclampsia. Your doctor may have you come in for additional blood pressure readings and blood and urine tests.

Your provider may check your baby’s health with:

• Ultrasound. This is a prenatal test that uses sound waves and a computer screen to make a picture of your baby in the womb. Ultrasound checks that your baby is growing at a normal rate. It also lets your provider look at the placenta and the amount of fluid around your baby to make sure your pregnancy is healthy.
• Nonstress test. A nonstress test is a simple procedure that checks how your baby’s heart rate reacts when your baby moves.
• Biophysical profile. This test combines the nonstress test with an ultrasound. A biophysical profile uses an ultrasound to measure your baby’s breathing, muscle tone, movement and the volume of amniotic fluid in your uterus.

The cure for preeclampsia is the birth of your baby. Treatment depends on how severe your preeclampsia is and how far along you are in your pregnancy. Even if you have mild preeclampsia, you need treatment to make sure it doesn’t get worse.

In addition to tests that might diagnose preeclampsia or similar problems, health care providers 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
• Urine analysis. Your doctor will ask you to collect your urine for 24 hours, for measurement of the amount of protein in your urine. A single urine sample that measures the ratio of protein to creatinine — a chemical that’s always present in the urine — also may be used to make the diagnosis.
• A physical exam to look for swelling in the mother’s face, hands, or legs as well as abdominal tenderness or an enlarged liver

Preeclampsia treatment

The only cure for preeclampsia is delivery. You’re at increased risk of seizures, placental abruption, stroke and possibly severe bleeding until your blood pressure decreases. Of course, if it’s too early in your pregnancy, delivery may not be the best thing for your baby.

If you’re diagnosed with preeclampsia, your doctor will let you know how often you’ll need to come in for prenatal visits — likely more frequently than what’s typically recommended for pregnancy. You’ll also need more frequent blood tests, ultrasounds and nonstress tests than would be expected in an uncomplicated pregnancy.

Medications

Possible treatment for preeclampsia may include:

• Medications to lower blood pressure. These medications, called antihypertensives, are used to lower your blood pressure if it’s dangerously high. Blood pressure in the 140/90 millimeters of mercury (mm Hg) range generally isn’t treated. Although there are many different types of antihypertensive medications, a number of them aren’t safe to use during pregnancy. Discuss with your doctor whether you need to use an antihypertensive medicine in your situation to control your blood pressure.
• Corticosteroids. If you have severe preeclampsia or HELLP syndrome, corticosteroid medications can temporarily improve liver and platelet function to help prolong your pregnancy. Corticosteroids can also help your baby’s lungs become more mature in as little as 48 hours — an important step in preparing a premature baby for life outside the womb.
• Anticonvulsant medications. If your preeclampsia is severe, your doctor may prescribe an anticonvulsant medication, such as magnesium sulfate, to prevent a first seizure.

If the pregnancy is at 37 weeks or later, the health care provider will usually want to deliver the fetus to treat preeclampsia and avoid further complications.

If the pregnancy is at less than 37 weeks, however, the woman and her health care provider may consider treatment options that give the fetus more time to develop, depending on how severe the condition is. A health care provider may consider the following options:

• If the preeclampsia is mild, it may be possible to wait to deliver. 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 if 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 and continuously. 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 and is at 34 weeks of pregnancy or later, the American College of Obstetricians and Gynecologists recommends delivery as soon as medically possible. If the pregnancy is at less than 34 weeks, health care providers will probably prescribe corticosteroids to help speed up the maturation of the fetal lungs before attempting delivery.

Preterm delivery may be necessary, 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 ³.

Mild preeclampsia treatment

Most women with mild preeclampsia after 37 weeks of pregnancy don’t have serious health problems. If you have mild preeclampsia before 37 weeks:

• Your provider checks your blood pressure and urine regularly. She may want you to stay in the hospital to monitor you closely. If you’re not in the hospital, your provider may want you to have checkups once or twice a week. She also may ask you to take your blood pressure at home.
• Your provider may ask you to do kick counts to track how often your baby moves. There are two ways to do kick counts: Every day, time how long it takes for your baby to move ten times. If it takes longer than 2 hours, tell your provider. Or three times a week, track the number of times your baby moves in 1 hour. If the number changes, tell your provider.
• If you’re at least 37 weeks pregnant and your condition is stable, your provider may recommend that you have your baby early. This may be safer for you and your baby than staying pregnant. Your provider may give you medicine or break your water (amniotic sac) to make labor start. This is called inducing labor.

Can taking low-dose aspirin help reduce your risk for preeclampsia and premature birth?

For some women, yes. If your provider thinks you’re at risk for preeclampsia, he may want you to take low-dose aspirin to help prevent it. Low-dose aspirin also is called baby aspirin or 81 mg (milligrams) aspirin. Talk to your doctor to see if treatment with low-dose aspirin is right for you.

You can buy low-dose aspirin over-the-counter, or your provider can give you a prescription for it. A prescription is an order for medicine from your provider. If your provider wants you to take low-dose aspirin to help prevent preeclampsia, take it exactly as she tells you to. Don’t take more or take it more often than your provider says.

If you’re at high risk for preeclampsia, your provider may want you to start taking low-dose aspirin (81 mg/day) after 12 weeks of pregnancy.

Severe preeclampsia treatment

If you have severe preeclampsia, you most likely stay in the hospital so your provider can closely monitor you and your baby. Your provider may treat you with medicines called antenatal corticosteroids. These medicines help speed up your baby’s lung development. You also may get medicine to control your blood pressure and medicine to prevent seizures (called magnesium sulfate).

If your condition gets worse, it may be safer for you and your baby to give birth early. Most babies of moms with severe preeclampsia before 34 weeks of pregnancy do better in the hospital than by staying in the womb. If you’re at least 34 weeks pregnant, your provider may recommend that you have your baby as soon as your condition is stable. Your provider may induce your labor, or you may have a c-section. If you’re not yet 34 weeks pregnant but you and your baby are stable, you may be able to wait to have your baby.

If you have severe preeclampsia and HELLP syndrome, you almost always need to give birth early. HELLP syndrome is a rare but life-threatening liver disorder.

HELLP stands for these blood and liver problems:

• H–Hemolysis. This is the breakdown of red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body.
• EL–Elevated liver enzymes. High levels of these chemicals can be a sign of liver problems.
• LP–Low platelet count (thrombocytopenia). Platelets help the blood clot.

About 2 in 10 women (20 percent) with severe preeclampsia develop HELLP syndrome. You may need medicine to control your blood pressure and prevent seizures. Some women may need blood transfusions. A blood transfusion means you have new blood put into your body.

Coping and support

Discovering that you have a potentially serious pregnancy complication can be frightening. If you’re diagnosed with preeclampsia late in your pregnancy, you may be surprised and scared to know that you’ll be induced right away. If you’re diagnosed earlier in your pregnancy, you may have many weeks to worry about your baby’s health.

It may help to learn about your condition. In addition to talking to your doctor, do some research. Make sure you understand when to call your doctor, how you should monitor your baby and your condition, and then find something else to occupy your time so that you don’t spend too much time worrying.

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