Preeclampsia is a pregnancy complication characterized by high blood pressure and signs of damage to another organ system, often the kidneys. Preeclampsia usually begins after 20 weeks of pregnancy in a woman whose blood pressure had been normal. Even a slight rise in blood pressure may be a sign of preeclampsia.
Left untreated, preeclampsia can lead to serious even fatal complications for both you and your baby. If you have preeclampsia, the only cure is delivery of your baby.
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 sometimes develops without any symptoms. 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 is 140/90 millimeters of mercury (mm Hg) or greater documented on two occasions, at least four hours apart is abnormal.
Other signs and symptoms of preeclampsia may include:
- Excess protein in your urine or additional signs of kidney problems
- Severe headaches
- Changes in vision, including temporary loss of vision, blurred vision or light sensitivity
- Upper abdominal pain, usually under your ribs on the right side
- Nausea or vomiting
- Decreased urine output
- Decreased levels of platelets in your blood
- Impaired liver function
- Shortness of breath, caused by fluid in your lungs
Sudden weight gain and swelling (edema) particularly in your face and hands often accompanies preeclampsia. But these things also occur in many normal pregnancies, so they’re not considered reliable signs of preeclampsia.
Early in pregnancy, new blood vessels develop and evolve to efficiently send blood to the placenta. In women with preeclampsia, these blood vessels don’t seem to develop properly. They’re narrower than normal blood vessels and react differently to hormonal signaling, which limits the amount of blood that can flow through them.
Causes of this abnormal development may include:
- Insufficient blood flow to the uterus
- Damage to the blood vessels
- A problem with the immune system
- Certain genes
Preeclampsia develops only as a complication of pregnancy. Risk factors include:
- A personal or family history of preeclampsia significantly raises your risk of preeclampsia.
- The risk of developing preeclampsia is highest during your first pregnancy.
- Each pregnancy with a new partner increases the risk of preeclampsia over a second or third pregnancy with the same partner.
- The risk of preeclampsia is higher for pregnant women older than 40.
- The risk of preeclampsia is higher if you’re obese.
- Preeclampsia is more common in women who are carrying twins, triplets or other multiples.
- Having babies less than two years or more than 10 years apart leads to a higher risk of preeclampsia.
Having certain conditions before you become pregnant such as chronic high blood pressure, migraine headaches, type 1 or type 2 diabetes, kidney disease, a tendency to develop blood clots, or lupus increases your risk of preeclampsia.
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. Surgical delivery (cesarean section or C-section) isn’t always advantageous unless other problems are present, such as a baby in breech presentation, or if a speedy delivery is necessary. If you have severe preeclampsia or you’re at less than 30 weeks gestation, a C-section may be necessary.
Complications of preeclampsia may include:
Lack of blood flow to the placenta. Preeclampsia affects the arteries carrying blood to the placenta. If the placenta doesn’t get enough blood, your baby may receive less oxygen and fewer nutrients. This can lead to slow growth, low birth weight or preterm birth. Prematurity can lead to breathing problems for the baby.
Placental abruption. Preeclampsia increases your risk of placental abruption, in which the placenta separates from the inner wall of your uterus before delivery. Severe abruption can cause heavy bleeding and damage to the placenta, which can be life-threatening for both you and your baby.
HELLP syndrome. HELLP — which stands for hemolysis (the destruction of red blood cells), elevated liver enzymes and low platelet count — syndrome 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.
Eclampsia. When preeclampsia isn’t controlled, eclampsia — which is essentially preeclampsia plus seizures — can develop. Symptoms that suggest imminent eclampsia include upper right abdominal pain, severe headache, vision problems and change in mental status, such as decreased alertness. Because eclampsia can have serious consequences for both mom and baby, delivery becomes necessary, regardless of how far along the pregnancy is.
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.
Tests and diagnosis
To diagnose 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
- Visual disturbances
Previously, preeclampsia was only diagnosed if a pregnant woman had high blood pressure and protein in her urine. However, experts now know that it’s possible to have preeclampsia, yet never have protein in the urine.
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.
Treatments and drugs
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 non-stress tests than would be expected in an uncomplicated pregnancy.
Possible treatment for preeclampsia may include:
- Medications to lower blood pressure.
- Anticonvulsant medications.
Bed rest used to be routinely recommended for women with preeclampsia. But research hasn’t shown a benefit from this practice, and it can increase your risk of blood clots, as well as impact your economic and social lives. For most women, bed rest is no longer recommended.
Severe preeclampsia may require that you be hospitalized. In the hospital, your doctor may perform regular nonstress tests or biophysical profiles to monitor your baby’s well-being and measure the volume of amniotic fluid. A lack of amniotic fluid is a sign of poor blood supply to the baby.
If you’re diagnosed with preeclampsia near the end of your pregnancy, your doctor may recommend inducing labor right away. 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 severe cases, it may not be possible to consider your baby’s gestational age or the readiness of your cervix. If it’s not possible to wait, your doctor may induce labor or schedule a C-section right away. During delivery, you may be given magnesium sulfate intravenously to prevent seizures.
After delivery, expect your blood pressure to return to normal within 12 weeks but usually much sooner. If you need pain-relieving medication after your delivery, ask your doctor what you should take.
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, and the research into vitamin D is ongoing.
In certain cases, however, you may be able to reduce your risk of preeclampsia with:
- Low-dose aspirin.
- Calcium supplements.
It’s important that you don’t take any medications, vitamins or supplements without first talking to your doctor.
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.
When to see a doctor
Make sure you attend your prenatal visits so that your care provider can monitor your blood pressure. Contact your doctor immediately or go to an emergency room if you have severe headaches, blurred vision, severe pain in your abdomen or severe shortness of breath.
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.
Source: Mayo Clinic