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Each prenatal visit, your provider slaps a cuff on your upper arm, squeezes a bulb until you feel a tight hug, then, relief. For pregnant folks, this quick test is as standard as a weight check or peeing in a cup. And unless you have a history of blood pressure issues, there’s a good chance you never gave this prenatal test another thought. But you should. High blood pressure (hypertension) in pregnancy is a major cause of complications—and even death—for expecting parents and their babies—and it’s a problem that’s getting worse.

The latest numbers show that about 20% of births are impacted by high blood pressure during pregnancy—a rate that doubled between 2007 and 2019, according to research in the Journal of the American Heart Association. Right now, America has one of the highest maternal mortality rates for high blood pressure-related problems when compared to other high-income countries. It’s no wonder that the American Heart Association has dubbed hypertension in pregnancy a “public health crisis.”

The best defense against high blood pressure in pregnancy? Knowledge. Here’s what you need to know about hypertension in pregnancy.

What is high blood pressure?

Your blood pressure is the measure of how hard your blood is pumping. More specifically, it gauges the pressure (or force) of your blood pushing against blood vessel walls (arteries). When you have high blood pressure, the force against your arteries is higher than normal. Your arteries bring blood from your heart to your lungs, where it picks up and carries oxygen to your organs and tissues. That means, when the pressure against your arteries is high, this entire cardiovascular system is impacted. The tricky thing about blood pressure is that it often changes throughout the day. So, you may have one high reading at, say, noon, but when it’s measured again three hours later, it may be just fine.

Why does blood pressure change in pregnancy?

Your body goes through so many changes during pregnancy, and your cardiovascular system is far from spared. For example, your heart now needs to work harder to keep up with the increased blood flow that goes hand-in-hand with pregnancy. Plus, your blood vessels now need to relax more to support this change. All of this has the potential to impact your blood pressure. 

What is considered high blood pressure during pregnancy?

The story of blood pressure is told in two numbers, separated by a slash, such as 110/80 mmHg (or 110 over 80). The top number (110) is the pressure against your artery walls when the heart contracts. This is systolic blood pressure. The bottom number (80) is the pressure against the artery walls when the heart relaxes between contractions. This is diastolic blood pressure. Here’s the breakdown of what these numbers mean, according to the American College of Obstetricians and Gynecologists (ACOG):

  • Normal Blood Pressure: Anything under 120/80 mmHg is considered normal blood pressure.

  • Elevated Blood Pressure: When systolic blood pressure (top number) ranges from 120 to 129 mmHg and diastolic (bottom number) is below 80 mmHg it’s considered elevated. It’s not quite classified as high, but it’s higher than ideal.

  • High Blood Pressure (stage 1): The systolic number falls between 130-139 mmHg or the diastolic number is between 80-89 mmHg.

  • High Blood Pressure (stage 2): The systolic number is 140 mmHg or above or the diastolic number is 90 mmHg or higher.

  • Severe Hypertension: This is defined as having systolic blood pressure of 160 mmHg or higher and/or diastolic blood pressure of 110mm Hg or higher. Pregnant individuals with severe hypertension are at risk of very serious complications.

Types of High Blood Pressure During Pregnancy

High blood pressure in pregnancy is actually classified as “hypertensive disorders of pregnancy” or HDP, and it encompasses a few different types of high blood pressure.

Chronic Hypertension

Chronic hypertension either rears its head prior to pregnancy—or it develops before 20 weeks of pregnancy. This type of high blood pressure in pregnancy sticks around after birth, too. If you were on blood pressure meds before pregnancy, you have chronic hypertension.

Gestational Hypertension

Gestational hypertension may be referred to as “high blood pressure during pregnancy” or “pregnancy-induced hypertension.” This type of high blood pressure occurs after the 20-week mark of pregnancy and it has not yet impacted other organs. Most folks with gestational hypertension only experience a small increase in blood pressure. Gestational hypertension often goes away after giving birth.

Preeclampsia

When high blood pressure in pregnancy or shortly after delivery starts to affect other organs, like the kidneys or liver, it is called preeclampsia. Nearly one in four moms-to-be with chronic hypertension develop preeclampsia during pregnancy, usually after 20 weeks, and often in the third trimester. (When preeclampsia develops before 34 weeks of pregnancy, it is called early-onset preeclampsia.) If preeclampsia worsens it can develop into what’s called “severe features” of preeclampsia, marked in part by a systolic blood pressure exceeding 160 or diastolic reading of 110. Learn how to spot the signs of preeclampsia.

Who’s at risk for high blood pressure in pregnancy?

While the exact cause of high blood pressure in pregnancy is unknown, there are certain risk factors and conditions that appear to elevate risk, including…

  • Diabetes or gestational diabetes

  • Expecting multiples

  • Family history of high blood pressure in pregnancy

  • Gestational hypertension or preeclampsia during a past pregnancy

  • Immune disorder, such as lupus

  • Kidney disease

  • Obesity

  • An age over 40 or under 20

  • Being Black, American Indian, or Alaska Native

What are the symptoms of high blood pressure in pregnancy?

Your care provider will check your blood pressure at every prenatal visit, which is a good thing especially because symptoms of gestational hypertension are so stealth that most people don’t even notice their blood pressure is high. That said, some do experience these signs of high blood pressure in pregnancy:

  • Abdominal pain (upper right)

  • Difficulty breathing

  • Headaches

  • Nausea or vomiting in second half of pregnancy

  • Sudden weight gain

  • Swelling (edema) of the of face or hands

  • Urinating only a little at a time

  • Vision changes, such as seeing spots

Reach out to your midwife or physician if you are experiencing any of these high blood pressure signs.

What are possible complications of high blood pressure in pregnancy?

Not every parent-to-be with high blood pressure during pregnancy will go on to develop complications, such as preeclampsia. However, hypertension in pregnancy does elevate the risk of:

  • Cardiovascular Issues: Long-term cardiovascular issues include heart attack, heart failure, and stroke. Research shows that you’re most vulnerable for developing these problems the first 10 years following delivery.

  • Cesarean Birth: According to the March of Dimes, high blood pressure in pregnancy boosts the likeliness of a c-section birth.

  • Eclampsia: This complication is associated with preeclampsia and causes seizures and may lead to coma. Eclampsia is a medical emergency.

  • Future Hypertension: Although gestational hypertension often goes away after birth, it may increase your chances of developing high blood pressure down the road.

  • Gestational Diabetes: This type of diabetes occurs in pregnancy. You should be tested for gestational diabetes between 24 to 28 weeks of pregnancy.

  • HELLP Syndrome: HELLP stands for hemolysis (H), elevated liver enzymes (EL), low platelet count (LP) and it leads to serious blood and liver problems. HELLP syndrome is a medical emergency.

  • Kidney Failure: Those with high blood pressure during pregnancy may face double the risk for kidney disease within several years after giving birth, according to a study in the journal Hypertension.

  • Placental Abruption: Hypertension in pregnancy increases the chance that your placenta will separate from the wall of your uterus before birth. If this happens, your baby may not get enough oxygen and nutrients in the womb.

  • Postpartum Hemorrhage: High blood pressure in pregnancy predisposes birthing individuals to a brisker blood loss after delivery.

  • Pulmonary Edema: Here, fluid fills the lungs, leading to shortness of breath.

How High Blood Pressure in Pregnancy Affects Baby

The good news? When hypertension is caught early in pregnancy, most parents-to-be go on to deliver healthy babies. But the more severe your high blood pressure is, the bigger the risk for serious complications. One of the reasons: Hypertension in pregnancy can reduce the blood flow to the placenta, which can lead to your little one not getting all the nutrients and oxygen they need to grow and thrive, resulting in complications like preterm birth, low birth weight, even stillbirth and neonatal death, which is when a baby dies in their first 28 days of life.

How to Treat and Manage High Blood Pressure in Pregnancy

One of the best ways to manage high blood pressure during pregnancy is by going to all your prenatal care checkups! Don’t be surprised if your doctor puts extra visits on the calendar to monitor your blood pressure and test your urine for preeclampsia.

Your care provider may also advise you to…

  • Check blood pressure at home, usually weekly

  • Exercise for 30 minutes a day to help prevent high blood pressure from morphing into preeclampsia

  • Eat fresh and whole foods, and avoid processed foods, like high sodium packaged meals

  • Continue to avoid smoking and drinking alcohol

  • Take a daily low-dose of aspirin, which may reduce the risk of developing preeclampsia. This treatment, which usually starts at 12 to 14 weeks of pregnancy, is often recommended for those at a high risk for preeclampsia.

  • Take a prescription blood pressure-lowering medicine, like labetalol or methyldopa, as directed. A 2021 report in the journal Hypertension notes that this type of treatment can halve the incidence of severe hypertension. (ACE inhibitors, angiotensin II receptor blockers, and renin inhibitors, on the other hand, need to be avoided during pregnancy.)

  • Monitor your baby-to-be by way of ultrasounds, nonstress tests, a biophysical profile, and/or a daily kick count.

  • Taking magnesium sulfate, a medication that prevents seizures, if you have severe preeclampsia. Some research suggests that it may help reduce the risk of cerebral palsy for little ones born before 32 weeks, too.

Will I need to deliver early with high blood pressure in pregnancy?

Probably. If your condition remains stable, ACOG recommends delivering your baby 1 to 3 weeks before your due date, which translates to about 37 to 39 weeks pregnant. If you or baby-to-be have developed any complications, you may need to deliver your little one earlier. (If you’re between 23 and 37 weeks pregnant, your care provider will likely recommend corticosteroids to help speed your baby-to-be’s lung development.)

Does gestational hypertension go away after birth?

Gestational hypertension and preeclampsia most often resolve by 12 weeks postpartum. But experts urge you not to wait it out! If you experienced hypertension during pregnancy, you are at an increased risk for developing severe hypertension in the postpartum period. That’s why ACOG recommends those who had high blood pressure in pregnancy to see your care provider no later than 7 to 10 days postpartum. And if you had severe hypertension during pregnancy, you should see your provider within 72 hours of giving birth. It’s also a good idea to continue to test your blood pressure at home in the weeks following your baby’s birth.

Both steps are critical, especially since more than half of postpartum strokes occur within 10 days of discharge—and more than 50% of pregnancy-related maternal deaths occur after the birth of the infant. 

More on Pregnancy:

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REFERENCES

  • Temporal Trends in Adverse Pregnancy Outcomes in Birthing Individuals Aged 15 to 44 Years in the United States, 2007 to 2019. Journal of the American Heart Association. May 2022
  • American Heart Association: High blood pressure treatment in pregnancy is safe and could reduce mother's risks
  • The American College of Obstetricians and Gynecologists (ACOG): What’s the Concern About High Blood Pressure During Pregnancy? An Ob-Gyn Explains
  • Cleveland Clinic: High Blood Pressure (Hypertension) During Pregnancy
  • ACOG: Preeclampsia and High Blood Pressure During Pregnancy
  • Hypertension in Pregnancy: Diagnosis, Blood Pressure Goals, and Pharmacotherapy: A Scientific Statement From the American Heart Association. Hypertension. December 2021
  • March of Dimes: High blood pressure, preeclampsia and pregnancy
  • Stanford Medicine: Pregnancy and High Blood Pressure
  • How much does hypertension in pregnancy affect the risk of future cardiovascular events? European Heart Journal Supplements. April 2023
  • Hypertensive Disorders of Pregnancy With and Without Prepregnancy Hypertension Are Associated With Incident Maternal Kidney Disease Subsequent to Delivery. Hypertension. February 2022
  • Yale Medicine: Hypertension (High Blood Pressure) During Pregnancy
  • Mayo Clinic, Pregnancy week by week: High blood pressure and pregnancy: Know the facts
  • Mayo Clinic: Preterm labor
  • Postpartum hypertension. Canadian Medical Association Journal. July 2017
  • UTSouthwestern Medical Center: Postpartum hypertension: When a new mom's blood pressure is too high
  • ACOG: Optimizing Postpartum Care
  • UTSouthwestern Medical Center:  Postpartum hypertension: When a new mom's blood pressure is too high

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.