Preeclampsia is a pregnancy complication for some women that appears at about 20 weeks of pregnancy. It is characterized by high blood pressure and signs that some of your organs, usually your kidneys or liver, are not working as they should be.

Woman holding tabletWoman holding tabletWoman checking in for clinic visit

What causes preeclampsia?

Experts still aren’t sure what exactly causes preeclampsia to happen. Some think preeclampsia has to do with the placenta, the organ that delivers oxygen and nutrients to your baby. During pregnancy, the placenta develops a web of blood vessels that transport blood efficiently to the baby. Problems with the development of these blood vessels can lead them to be overly narrow or respond differently to hormones. This contributes to the high blood pressure and organ stress that characterizes preeclampsia.

In addition, research is ongoing about the role that genes, autoimmune diseases, and blood vessel problems may play in preeclampsia.

Risk factors

Even if the exact cause of preeclampsia is not known, experts have identified some factors that increase your risk of developing preeclampsia:

  • Age. You are at greater risk if you are under 18 or over 40 years old.
  • Being overweight or obese when you become pregnant.
  • First pregnancy. The risks for preeclampsia are greatest with your first pregnancy
  • Having a family history of preeclampsia.
  • Having chronic high blood pressure (chronic hypertension) before getting pregnant or early in your pregnancy.
  • Having twins, triplets, or multiples.
  • Pregnancy with a new partner. A pregnancy with a new partner increases your risk for preeclampsia more than having a second pregnancy with the same partner.
  • Previous pregnancies. You are more at risk if you had preeclampsia, intrauterine growth retardation (IUGR), preterm birth, placental abruption, or fetal death in a past pregnancy.
  • Using in vitro fertilization.

Symptoms of preeclampsia

Preeclampsia symptoms can range from mild to severe. You may only find out you have preeclampsia after a regular prenatal check-up.

The most common symptom of preeclampsia is high blood pressure: blood pressure over 140/90 milligrams of mercury (mmHg) that occurs twice at least 4 hours apart is considered abnormal.

Signs of preeclampsia that may appear during your prenatal exam include:

  • Decreased levels of platelets in your blood (thrombocytopenia).
  • Presence of liver enzymes and abnormal proteins in your blood. This shows impaired liver function.
  • Protein in your urine (proteinuria). This shows damage or distress to your kidneys.

Other symptoms include:

  • Belly pain, usually on the right side of your abdomen.
  • Blurred vision, or seeing flashes and spots.
  • Decreased urine output.
  • Dizziness.
  • Headache.
  • Nausea or vomiting.
  • Rapid weight gain (2-5 pounds or more in one week).
  • Trouble breathing.

Note that swelling of your hands, feet, and face can happen throughout pregnancy, so it is not a reliable sign of preeclampsia.

Don’t wait to call.

It can be hard to tell on your own if these symptoms are a normal part of pregnancy or not, especially if this is your first pregnancy. If you have any concerns, don’t hesitate to call your doctor.

If you experience vomiting, severe pain, shortness of breath, or visual disturbances, seek immediate medical attention.

How preeclampsia is diagnosed

Many cases of preeclampsia are caught during a routine prenatal check-up during your second trimester.

However, if you have any symptoms of preeclampsia, don’t wait until your check-up. Call your healthcare provider right away to schedule an appointment.

Criteria for a preeclampsia diagnosis

To be diagnosed with preeclampsia, you must have high blood pressure and at least one of the following signs or symptoms:

  • Fluid in lungs.
  • Impaired liver function.
  • Low platelet count.
  • New vision problems or headache.
  • Protein in urine.

Your healthcare provider will start by doing a physical exam and asking you about your symptoms. They will take your blood pressure. An abnormal reading is considered a blood pressure over 140/90 milligrams of mercury (mmHg).

Having one abnormal reading does not necessarily mean you have preeclampsia. Instead, your doctor may ask you to return in 4 hours and take another measure. Having two abnormal blood pressure readings 4 hours apart is part of the criteria for diagnosing preeclampsia.

Diagnostic tests

If your healthcare provider suspects preeclampsia, they will likely order one or more of the following tests:

Blood test. A sample of your blood will be analyzed for kidney function, creatinine levels, liver function, platelet counts, and red blood cell count. Abnormalities in these results may indicate preeclampsia. Your healthcare provider will also use them to check for HELLP syndrome (see above).

Fetal ultrasound. Problems with the placenta’s blood vessels can prevent your baby from getting enough oxygen and nutrients. This can lead to restricted fetal growth. If your healthcare provider suspects preeclampsia, they may recommend doing a fetal ultrasound. Based on the ultrasound, they can estimate the size and weight of your baby and amniotic fluid and see if they are normal. Fetal growth will have to be closely monitored if you have preeclampsia. Fetal ultrasounds are often combined with nonstress tests in a test known as a biophysical profile.

Nonstress test. A nonstress test involves measuring your baby’s heart rate and seeing how it responds when the baby moves. This tells you about the amount of oxygen your baby has access to and indicates their overall health.

Urine test. Your healthcare provider will use a dipstick to test for protein in your urine. If protein is found during the spot check, then they will ask you to collect your urine over 24 hours for further testing. Passing more than 300 mg of protein in 24 hours is a sign of kidney problems. They may also check your urine for its protein to creatinine ratio. Creatinine is a chemical that is always found in urine. A ratio of .3mg/dl indicates that about 300 mg of protein is being passed in your urine over 24 hours.

Complications of preeclampsia

With close monitoring, preeclampsia can be managed. However, left untreated, it can lead to serious and life-threatening health complications for you and your baby. Complications of preeclampsia include:

Eclampsia. Eclampsia is preeclampsia with seizures. Severe preeclampsia may develop into eclampsia, although there is no good way to predict if this will happen. Eclampsia is dangerous to both you and your baby, and you will likely need to deliver immediately.

Fetal growth restriction. Problems with the placenta’s blood vessels can restrict the flow of essential nutrients to your baby. This can lead to slower growth and low birth weight.

HELLP Syndrome. HELLP stands for hemolysis (destruction of red blood cells), elevated liver enzymes (which indicate liver damage), and low platelet count.

HELLP syndrome is a severe version of preeclampsia that develops later in pregnancy or shortly after delivery. It can lead to stroke or liver rupture, which can be life-threatening.

Organ damage. Severe preeclampsia can damage to your kidney, liver, lungs, eyes, or heart. Stroke and brain injury can also result from having a stroke or seizure.

Placental abruption. This is when the placenta breaks away from the uterine wall before delivery. It causes severe, sometimes life-threatening bleeding for you and your baby. Placental abruption can cause preterm birth or even stillbirth.

Postpartum hemorrhage. Preeclampsia increases your risk of severe bleeding after delivery. This is known as postpartum hemorrhage, and it can be life-threatening.

Premature birth. Severe preeclampsia can threaten you and your baby, and you may need to deliver early. Since your baby is still developing lungs and vital organ systems throughout the third trimester, premature birth can lead to breathing and other problems for your baby.

Treating preeclampsia

The only real cure for preeclampsia is delivery. No medication or therapy that can make it go away. Instead, you and your doctor will need to closely monitor your pregnancy and talk about when you may need to deliver your baby.


If you have mild preeclampsia, your doctor may recommend that you come in once or twice a week for monitoring. You will likely get blood tests, urine tests, and ultrasounds. This way, your doctor can keep an eye on you and your baby’s health and whether you will need to deliver early.

Your doctor may also recommend the following:

  • Bed rest. This means limiting your physical activity, avoiding lifting weight, and resting in bed often.
  • Checking your blood pressure at home. You will need a blood pressure machine to do this. Call your doctor if your blood pressure changes.
  • Doing kick counts. This involves counting the number of times your baby moves over a certain period. For instance, you may measure how long it takes your baby to move 10 times. If it takes longer than 2 hours, you should call your doctor.

For severe preeclampsia, your provider may recommend you be monitored in a hospital, so you can get immediate medical attention if needed.


Severe preeclampsia may require medications, such as:

  • Antihypertensive medications. These medications work to lower your blood pressure if it is dangerously high. However, many antihypertensives should not be taken with pregnancy, so you will need to talk to your doctor about which medication is right for you.
  • Corticosteroids. These medications may be prescribed if you have severe preeclampsia or HELLP syndrome. They can help improve your platelet count and liver function. They also help your baby’s lungs to develop more rapidly.
  • Anticonvulsant medications. Anticonvulsants like magnesium sulfate work to prevent seizures. Magnesium sulfate also helps slow preterm labor and prevent brain damage for a preterm baby. It is given intravenously (through an IV) in a hospital.


As noted, delivery is the only real cure for preeclampsia. Depending on your condition and your baby’s health, your doctor might recommend that you deliver early.

  • Mild preeclampsia. For mild preeclampsia, your doctor may recommend inducing labor at 37 weeks. At 37 weeks, your baby’s lungs are well developed, and they are less likely to experience complications. Your doctor will give you medication or break the amniotic sac to start labor. Depending on your condition and health, your doctor may also recommend having a Cesarean section (a C-section).
  • Severe preeclampsia. If you have severe preeclampsia, HELLP syndrome, or eclampsia, you will need to deliver right away, regardless of your baby’s gestational age. You will likely receive an infusion of magnesium sulfate to prevent seizures. Depending on their gestational age, your baby may need to be placed in an intensive care unit.

After you deliver, the symptoms of preeclampsia should gradually go away. It may take as many as 12 weeks for you to return to full health.

Postpartum preeclampsia treatment

Postpartum preeclampsia is a rare form of preeclampsia that develops after you deliver. It usually comes within 48 hours after delivery, but it may develop as much as 6 weeks later. The treatment for postpartum preeclampsia usually involves one or more of the following medications:

  • Antihypertensive medications. These medications work by lowering your blood pressure. They are usually safe to take even if you are breastfeeding.
  • Anticonvulsant medications. If you have severe postpartum preeclampsia, your doctor may give you an infusion of magnesium sulfate to prevent seizures. The infusion is given over a 24-hour period. During this time your blood pressure and urine output will be monitored closely.

Preeclampsia outlook

Getting diagnosed with a potentially serious pregnancy complication can be scary. You might be alarmed if you’re told that you need to deliver early. If you’re diagnosed early in your pregnancy, you might worry about your baby’s health and wellbeing.

These fears and worries are valid. Learning about your condition, talking with your doctor, and finding a medical team that has both empathy and expertise can help you navigate this challenging time.


American College of Obstetricians and Gynecologists. Preeclampsia and High Blood Pressure During Pregnancy (

National Institute of Child Health and Human Development (NICHD). Who is at risk of preeclampsia? (

MedlinePlus: National Library of Medicine. Preeclampsia (