During pregnancy, a person’s blood pressure should stay within the normal range. Very high or low blood pressure requires medical attention.
According to the American Heart Association (AHA), a healthy person should have a blood pressure reading of less than 120/80 millimeters of mercury (mm HG).
The top number, or systolic, measures blood pressure when the heart contracts. The lower number, or diastolic, measures the blood pressure when the heart is between beats.
Keep reading for more information on blood pressure during pregnancy and steps a pregnant woman can take to keep their blood pressure under control.
The American College of Obstetricians and Gynecologists (ACOG) state that a pregnant woman’s blood pressure should also be within the healthy range of less than 120/80 mm Hg.
If blood pressure readings are higher, a pregnant woman may have elevated or high blood pressure. If high blood pressure occurs during pregnancy, it may indicate serious complications such as preeclampsia.
It is important to track and manage blood pressure throughout pregnancy.
Blood pressure is the amount of pressure the blood places against the blood vessels walls with each heartbeat. A person can experience elevated or high blood pressure, or hypertension, during pregnancy. This is when the blood puts more pressure than normal against the artery walls.
During pregnancy, high blood pressure is also known as gestational hypertension. Gestational hypertension occurs if the woman’s blood pressure is within the normal range for the first 20 weeks of pregnancy and then increases to 140/90 mm Hg or higher during the second half of the pregnancy.
Experts do not know the exact cause of gestational hypertension, but according to Cedars-Sinai, potential risk factors include:
- having kidney disease
- being younger than 20 or older than 40
- being of African American descent
- having diabetes
- having a history of high blood pressure
- having multiple pregnancies
In most cases, hypertension goes away after delivery.
ACOG indicate that gestational hypertension can cause complications or increase the risk of complications, such as:
- preeclampsia and other hypertensive disorders of pregnancy typically occur after the 20th week of pregnancy and can lead to problems with the liver, kidney, or other organs
- preterm delivery.
- fetal growth restriction, which is a condition in which a lack of nutrients and oxygen can lead to lower birth weight
- cesarean delivery
- placental abruption, which occurs when the placenta separates from the wall of the uterus
Women who have high blood pressure before pregnancy should talk to their doctor or midwife. Their provider will likely closely monitor them and the fetus to make sure they are safe during the pregnancy.
In some cases, high blood pressure during pregnancy may not cause any symptoms.
If high blood pressure occurs as a result of preeclampsia, common symptoms include:
- swelling, especially in the hands or face
- a headache that does not go away with medication
- rapid weight gain
- only able to make small amounts of urine
- visual disturbances
- vomiting or nausea that begins or worsens after the 20th week of pregnancy
- changes in vision
- pain near the stomach or on the upper right side of the abdomen
- blurred vision
- inability to concentrate
- cold or clammy skin
- rapid breathing
For most adults, healthy blood pressure is usually less than 120/80 mm Hg. Low blood pressure, or hypotension, occurs when the blood pressure drops below 90/60 mm Hg.
Some people have a naturally low blood pressure, but a sudden drop can cause symptoms to develop.
Any pregnant woman who has any concerns over their health or the developing fetus should talk to or see their doctor or midwife.
People who have high blood pressure or are at greater risk of developing high blood pressure might want to monitor their blood pressure at home.
A healthcare provider can likely recommend the best blood pressure cuffs to use.
If home monitoring indicates that blood pressure is too high or too low, contact a healthcare provider.
Any pregnant woman who experiences signs or symptoms of preeclampsia must seek immediate medical assistance.
There are several ways for a pregnant woman to manage blood pressure safely.
According to March of Dimes, a person can take the following steps:
- take approved blood pressure medication daily
- monitor blood pressure at home
- eat foods rich in nutrients and avoid salt, processed foods, and added sugars
- go to all medical checkups
- avoid drinking, smoking, and recreational drug use
- stay active through walking or other exercises unless otherwise instructed
Women who have high blood pressure during pregnancy should follow all instructions from their healthcare provider. They should notify their doctor or midwife if they have any changes in their blood pressure or feelings.
It is not always possible to prevent high blood pressure, but a person can take steps to keep their blood pressure at normal levels before and during pregnancy.
The Centers for Disease Control and Prevention (CDC) recommend a person take the following measures to prevent high blood pressure:
- talking to a healthcare provider before pregnancy about any existing health problems and medications
- getting regular and early prenatal care
- making sure all medications are safe to continue during pregnancy
- eating healthful foods
- exercising regularly
If a pregnant woman shows signs of low blood pressure, they should talk to their provider about the best course of action.
General treatment options for a person with low blood pressure include:
- increasing the amount of sodium in the diet
- increasing fluids
- maintaining light to moderate exercise
- standing from a sitting or lying position slowly
- avoiding alcohol
A pregnant woman should maintain their normal blood pressure throughout pregnancy.
Women with previous high blood pressure, multiples, or other risk factors have a greater chance of developing high blood pressure in later pregnancy.
High blood pressure during pregnancy has associations with serious pregnancy complications, including preeclampsia and other hypertensive disorders.
If blood pressure gets too high or low, a person should talk to their healthcare provider to determine the best course of treatment.