Everything You Need to Know About High Blood Pressure During Pregnancy

Medically Reviewed
a pregnant woman having her blood pressure checked
It's important to monitor your blood pressure during pregnancy.Shutterstock

Whether you have high blood pressure before becoming pregnant or develop it during pregnancy, monitoring and controlling your hypertension is important for your own health and your baby’s.

Women who have never had high blood pressure before may develop hypertension during pregnancy. When this happens after 20 weeks of pregnancy, it's known as gestational hypertension. This is a form of secondary hypertension caused by pregnancy, and it frequently goes away after delivery. (1)

RELATED: 6 Things You Should Know About High Blood Pressure

The Risk for High Blood Pressure During Pregnancy

If not treated, high blood pressure can be dangerous for the mother and the baby.

While many women with high blood pressure deliver healthy babies, hypertension can affect a mother's kidneys and increase her risk of heart disease, kidney disease, and stroke.

Other possible complications include:

Low birth weight Since high blood pressure can decrease the flow of nutrients to the baby through the placenta, the baby may not grow as expected.

Preterm delivery If the placenta is not providing enough nutrients and oxygen to your baby, your doctor may recommend early delivery.

Placental abruption This is a medical emergency that occurs when the placenta prematurely detaches from the wall of the uterus.

Cesarean delivery Women with hypertension are more likely to have a C-section than women with normal blood pressure.

Preeclampsia This severe condition, also called toxemia of pregnancy, can be life-threatening to both the mother and baby. It is characterized by high blood pressure and signs of damage to an organ system, most commonly the liver and kidneys.

HELLP syndrome This stands for hemolysis (the destruction of red blood cells), elevated liver enzymes, and low platelet count, and is a more severe form of preeclampsia. Symptoms include nausea and vomiting, headache, and upper right abdominal pain. HELLP can become life-threatening very quickly, as it may damage several organ systems.

If you have high blood pressure before you get pregnant, you're more likely to have certain complications during pregnancy than women who have normal blood pressure.

And women who develop gestational hypertension are at risk for complications, too. (2,3)

What Is Preeclampsia?

Preeclampsia is a condition in which a pregnant woman experiences an increase in blood pressure and signs of damage to another organ system.

The condition usually develops after 20 weeks of pregnancy, and affects the placenta. It's a leading cause of fetal complications, and can also affect the mother's kidney, liver, and brain. (3)

In some cases, preeclampsia can lead to seizures in pregnant women. This condition is called eclampsia. (2)

In the past, preeclampsia was diagnosed only if a pregnant woman had high blood pressure and protein in her urine.

It's now known that pregnant women can have preeclampsia without the presence of protein in their urine. (3)

According to the National Institute of Child Health and Human Development, the exact number of women who develop preeclampsia is not known, but some estimates say as many as 2 to 8 percent of pregnancies worldwide are affected by the condition. In the United States, that number is about 3.4 percent. (4)

The following are some signs and symptoms of preeclampsia:

  • Increased blood pressure
  • Decreased levels of platelets in your blood
  • Impaired liver function
  • Excess protein in the urine (proteinuria)
  • Decreased urine output
  • Swelling of the face or hands
  • A headache that will not go away
  • Seeing spots or changes in eyesight
  • Pain in the upper abdomen or shoulder
  • Nausea and vomiting during the second half of pregnancy
  • Sudden weight gain
  • Difficulty breathing or shortness of breath (2,3)

What Causes the Condition?

Doctors are still not clear why some women develop preeclampsia. But certain risk factors make it more likely, according to the American College of Obstetricians and Gynecologists. These include when women:

  • Are pregnant for the first time
  • Have had preeclampsia in a previous pregnancy
  • Have a family history of preeclampsia
  • Are obese
  • Have a history of chronic hypertension, kidney disease, or both
  • Are older than 40
  • Are pregnant with more than one baby
  • Have certain medical conditions like diabetes mellitus, thrombophilia, or lupus
  • Had in vitro fertilization (2)
  • Are African-American

What Is Postpartum Preeclampsia?

Postpartum preeclamspia is a serious disease that can develop in any woman immediately after childbirth up to six weeks after the baby is born. (5) The condition can result in seizures, organ damage, stroke, or death. According to the Preeclampsia Foundation, "97 percent of maternal deaths related to preeclampsia and other hypertensive disorders of pregnancy occur during pregnancy and within six weeks postpartum." (5)

Signs and symptoms of postpartum preeclampsia are often the same as symptoms of preeclampsia, and include:

  • Swelling in the hands and feet
  • Severe headaches
  • Stomach pain
  • Decreased urination (5,6)

How Is Preeclampsia Treated?

Although there is no known cure for preeclampsia, delivery of your baby is often indicated to treat the condition.

Other treatment options your doctor may recommend include blood-pressure-lowering medications, bed rest, and, in severe cases, hospitalization to monitor your and your baby’s well-being. (7)

Additional reporting by Ashley Welch.

Editorial Sources and Fact-Checking

  1. High Blood Pressure and Women. American Heart Association. January 29, 2018.
  2. Preeclampsia and High Blood Pressure During Pregnancy. American College of Obstetricians and Gynecologists. September 2014.
  3. Preeclampsia Symptoms and Causes. Mayo Clinic. April 3, 2018.
  4. How Many Women Are Affected by or at Risk of Preeclampsia? Eunice Kennedy Shriver National Institute of Child Health and Human Development. January 31, 2017.
  5. Postpartum Preeclampsia: Moms Are Still at Risk After Delivery. Preeclampsia Foundation. May 2, 2018
  6. Postpartum Preeclampsia. Mayo Clinic. May 3, 2018.
  7. Preeclampsia Diagnosis and Treatment. Mayo Clinic. August 17, 2018.
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