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High Blood Pressure During Pregnancy


Lara A. Friel

, MD, PhD, University of Texas Health Medical School at Houston, McGovern Medical School

Reviewed/Revised Nov 2023
  • Chronic hypertension: Blood pressure was high before the pregnancy.

  • Gestational hypertension: Blood pressure became high for the first time after women had been pregnant for 20 weeks (usually after 37 weeks). This type of hypertension typically resolves within 6 weeks after delivery.

Preeclampsia Preeclampsia and Eclampsia Preeclampsia is new high blood pressure or worsening of existing high blood pressure that is accompanied by excess protein in the urine and that develops after the 20th week of pregnancy. Eclampsia... read more is another type of high blood pressure that develops during pregnancy. It is accompanied by protein in the urine. Preeclampsia is diagnosed and treated differently from other types of high blood pressure.

Women who have chronic hypertension are more likely to have potentially serious problems during pregnancy. However, the following problems are more likely to occur if either chronic or gestational hypertension is present:

The HELLP syndrome consists of hemolysis (the breakdown of red blood cells), elevated levels of liver enzymes (indicating liver damage), and a low platelet count, making blood less able to clot and increasing the risk of bleeding during and after labor.

During pregnancy, women with high blood pressure are monitored closely to make sure blood pressure is well-controlled, the kidneys are functioning normally, and the fetus is growing normally. However, premature detachment of the placenta cannot be prevented or anticipated. Often, a baby must be delivered early to prevent stillbirth or complications due to severe high blood pressure (such as stroke) in the woman.

Diagnosis of High Blood Pressure During Pregnancy

  • Routine measurement of blood pressure

Blood pressure is measured routinely at prenatal visits.

Usually if severe hypertension occurs for the first time in pregnant women, doctors do tests to rule out other causes of hypertension.

Treatment of High Blood Pressure During Pregnancy

  • For mild to moderate high blood pressure, reduced activity and, if needed, antihypertensive medications

  • For more severe high blood pressure, antihypertensive medications

  • Avoidance of certain antihypertensive medications

Medications may or may not be used, depending on how high blood pressure is and how well the kidneys are functioning. Use and choice of medications to treat chronic and gestational hypertension are similar. However, gestational hypertension often occurs late in pregnancy and does not require treatment with medications.

For mild to moderate high blood pressure (140/90 to 159/109 millimeters of mercury [mm Hg]), treatment depends on many factors. Doctors may recommend reducing physical activity to possibly help lower blood pressure. If reduced activity does not lower blood pressure, many experts recommend treatment with antihypertensive medications. Whether the benefits of these medications outweigh the risks is unclear. However, if the kidneys are not functioning normally, medications are needed. If high blood pressure is not controlled well, the kidneys may be damaged further.

For very high blood pressure (180/110 mm Hg or higher), women are evaluated immediately because risk of complications for women and/or the fetus is high. If women wish to continue the pregnancy despite the risk, they often require several antihypertensive medications. They may be hospitalized toward the end of the pregnancy. If their condition worsens, doctors may recommend ending the pregnancy.

Women are taught to check their blood pressure at home. Doctors periodically do tests to determine how well the kidneys and liver are functioning and do ultrasonography to determine how well the fetus is growing.

If pregnant women have moderately high to very high blood pressure, the baby is typically delivered at 37 to 39 weeks. It is delivered earlier if the fetus is growing slowly, the fetus is having problems, or the woman has severe preeclampsia.

Antihypertensive medications

Most antihypertensive medications Antihypertensive Drugs Antihypertensive Drugs used to treat high blood pressure can be used safely during pregnancy. They include

  • Methyldopa

  • Beta-blockers (most commonly, labetalol)

  • Calcium channel blockers (such as nifedipine)

However, angiotensin-converting enzyme (ACE) inhibitors are stopped during pregnancy, particularly during the last two trimesters. These medications can cause birth defects of the urinary tract in the fetus. As a result, the baby may die shortly after birth.

Angiotensin II receptor blockers are stopped because they increase the risk of kidney, lung, and skeletal problems and death in the fetus.

Aldosterone antagonists (spironolactone and eplerenone) are also stopped because they can cause a male fetus to develop feminine characteristics.

Did You Know...

  • Some medications used to treat high blood pressure and heart disorders—ACE inhibitors, angiotensin receptor blockers, aldosterone antagonists, and often thiazide diuretics—are usually stopped during pregnancy.

Thiazide diuretics are usually stopped because they can cause low potassium levels in the fetus. However, if other medications are ineffective or have intolerable side effects, women with chronic hypertension may be given thiazide diuretics (such as hydrochlorothiazide) during pregnancy.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Normodyne, Trandate
Adalat, Adalat CC, Afeditab CR, Nifediac CC, Nifedical XL, Procardia, Procardia XL
Aldactone, CAROSPIR
Esidrix, Ezide, HydroDIURIL, Microzide, Oretic, Zide
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