What Is Preeclampsia?

Pregnant woman having an ultrasound exam

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What Is Preeclampsia?

Preeclampsia is a very common pregnancy complication that causes high blood pressure, along with other symptoms such as protein in the urine. The condition is one of several hypertensive disorders of pregnancy and can be very serious for pregnant women and their babies. Other names for preeclampsia include toxemia, pregnancy-induced hypertension (PIH), and gestosis.

The hallmark of preeclampsia is that it involves high blood pressure that starts in the second half of pregnancy. Women with pre-existing hypertension can also get preeclampsia, but not all high blood pressure in pregnancy is preeclampsia. According to the Centers for Disease Control and Prevention, around 1 in 25 pregnant women develop the condition.

If you have high blood pressure during your pregnancy, your doctor will want to find out if preeclampsia is the cause.

Symptoms

In most cases, a sudden increase in blood pressure beginning sometime after 20 weeks gestation is the first sign of preeclampsia. Less often, blood pressure will rise slowly but steadily. In addition, excess protein in the urine, which is screened for during routine prenatal care visits, can signal kidney problems that often accompany high blood pressure in preeclampsia. 

Impact on the Mother

Because preeclampsia affects many organ systems in the body, increased blood pressure and increased protein in the urine are only two of the many symptoms that may be present. Other signs and symptoms of preeclampsia include:

  • Changes in vision, including temporary loss of vision, blurred vision, seeing spots, and/or light sensitivity
  • Decreased levels of platelets in the blood (thrombocytopenia)
  • Decreased urine output
  • Generalized swelling
  • Impaired liver function
  • Nausea or vomiting
  • Seizures
  • Severe headaches that don't go away
  • Shortness of breath
  • Sudden weight gain (also common in normal pregnancies)
  • Upper abdominal pain

In some women, preeclampsia becomes very severe. Any new or worsening symptoms should be reported to your doctor immediately. Severe, untreated preeclampsia can lead to eclampsia (a seizure disorder) or HELLP syndrome (a multi-organ syndrome). Both complications are very serious medical emergencies and can lead to the death of the mother and/or baby if not treated promptly.

HELLP syndrome encompasses the following problems:

  • H: Hemolysis, which is a breakdown of red blood cells
  • EL:  Elevated liver enzymes, which is a sign of damage to the liver
  • LP: Low platelet count, which inhibits clotting

In rare cases, preeclampsia can also occur after childbirth. When this happens, it is called postpartum preeclampsia. Onset is usually within 48 hours of delivery but can occur within six weeks postpartum. Symptoms are similar to typical preeclampsia, but this condition can be even more challenging, as the usual cure (delivery of the baby) is no longer available.

If you are experiencing any symptoms of preeclampsia during pregnancy or postpartum, contact your doctor right away. This condition can escalate quickly and sometimes requires emergency medical care.

Impact on the Baby

Preeclampsia affects babies primarily by reducing the amount of blood that flows through the placenta. Because the placenta is the fetus's only source of nourishment, this can cause babies to grow poorly, a condition called intrauterine growth restriction (IUGR). Stillbirth is also a potential complication.

Preeclampsia is a leading cause of preterm birth.

If a baby is not growing well or if the disease puts the mother's life in danger, doctors may decide that preterm delivery is the safest approach. If there is time before a preterm birth (before 37 weeks), doctors will usually administer steroids to the mother to speed the baby's lung development, or magnesium sulfate to prevent eclampsia in the mother and to help prevent cerebral palsy in the baby.

Risks from preterm delivery depend on how many weeks gestation the baby is at delivery. Preeclampsia usually happens near the end of pregnancy, and in these cases, the baby should have few or limited consequences of prematurity. However, if the baby must be delivered before 34 weeks, they may face more serious health issues.

Doctors will do everything they can to keep both mother and baby healthy until the baby can be safely delivered. Safely delaying childbirth is particularly crucial when preeclampsia starts in the second trimester. Prior to 23 to 24 weeks gestation, the baby is unlikely to survive outside the mother.

Diagnosis

If you have high blood pressure during pregnancy, your doctor will want to find out if preeclampsia or another condition, such as gestational diabetes, is the cause. Specifically, preeclampsia is diagnosed when high blood pressure and proteinuria (protein in the urine) is found in a pregnant woman who is beyond 20 weeks gestation.

Establishing that symptoms began after the midpoint of pregnancy is an important distinction, as women who had high blood pressure before becoming pregnant may sometimes meet the clinical criteria for preeclampsia, but are treated according to a different set of guidelines.

When blood pressure reaches or exceeds 140/90 mm Hg and a healthcare provider has documented this blood pressure reading on at least two occasions, spaced at least four hours apart, a diagnosis of preeclampsia is suspected. 

Causes

Doctors aren't sure what causes preeclampsia. However, they do know that the condition happens during pregnancy or in the immediate postpartum period. Researchers also believe there may be a genetic component, as the condition runs in families.

The formation and implantation of the placenta may play a role in preeclampsia, but this isn't always the case and the relationship is still unclear. There are many women with placentas that form normally who develop the disorder, and there are many women with poorly formed placentas who go on to have healthy pregnancies.

Although doctors aren't clear on what causes preeclampsia, they do know that certain women are at greater risk than others. Risk factors for preeclampsia include the following:

Because the risk factors for preeclampsia are so broad, doctors test every pregnant woman for signs of preeclampsia by measuring blood pressure and checking the urine for protein, often at every prenatal appointment.

Treatment

If preeclampsia goes untreated, it can lead to very serious complications for both the mother and the baby. In some cases, the condition can even be fatal. Unfortunately, the only cure for the condition is the delivery of the baby, which represents a unique challenge to healthcare providers as they balance the benefits of an early delivery for the mom with the risks of prematurity for the baby. 

Women with preeclampsia face an increased risk of seizures, placental abruption,​ and stroke. In severe cases, death is possible if the condition is left untreated.

If it is too early in the pregnancy to safely induce delivery, treatment includes close monitoring of the health of the mother and the baby. This careful monitoring may involve an increased frequency of prenatal exams, blood tests, ultrasounds, and nonstress tests. Your doctor may ask you to collect your urine for 12 or 24 hours to measure its total protein.

Additionally, other strategies may be used to control blood pressure and prevent complications until it's safe to induce labor. These include: 

  • Anticonvulsant medications to prevent seizures
  • Antihypertensive medications to lower blood pressure 
  • Bed rest 
  • Corticosteroids to improve liver and platelet function in the mother and help develop the baby's lungs to prepare for an early delivery 
  • Hospitalization

If you have signs of severe or worsening preeclampsia, you may require observation or treatment in a hospital setting. You will be monitored for signs of HELLP syndrome or eclampsia, and your baby's health and growth will be monitored.

Although medication may reduce symptoms, preeclampsia does not go away until both the baby and placenta have been delivered. After childbirth, the condition usually goes away. However, recovery is not immediate, and the mother may need to be in the hospital for several days or even weeks until they recover fully.

Prevention

Unfortunately, there is no sure way to prevent preeclampsia. While research is limited, some studies have shown that calcium supplementation or low-dose aspirin may help some women in specific circumstances. However, there is not enough evidence to recommend these remedies for all pregnant women.

Still, leading a healthy lifestyle may help reduce your risk of preeclampsia. Regular exercise and a diet high in vegetables and low in processed foods have been shown to reduce the incidence of the disorder for some women. Exercise and a healthy diet can also help to control obesity, chronic hypertension, and diabetes, which are all known risk factors for preeclampsia.

A Word From Verywell

Preeclampsia is a disease that can cause great harm, and even death, to both mothers and babies. Even in cases where preeclampsia seems mild, it can become very serious very quickly. If you have preeclampsia, even if you only have a few, mild symptoms, visiting your doctor often is very important in order to ensure that your condition is properly managed until your baby can be delivered.

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Article Sources
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