What is normal blood pressure for a pregnant woman?

High blood pressure in pregnancy, or hypertension, is how much pressure is placed on the walls of arteries when the heart pumps blood. Blood pressure is measured with two numbers, the top number (systolic) and the bottom number (diastolic) and reads 120/80, for example. The systolic number measures blood pressure when the heart pumps the blood to organs, and the diastolic number measures blood pressure when the heart retracts to fill with blood again.

High blood pressure during pregnancy can cause complications for the mother and the baby including preeclampsia, preterm birth and placental abruption. 

Types of High Blood Pressure in Pregnancy

Even if you have not had high blood pressure before pregnancy, you can develop high blood pressure during pregnancy, called gestational hypertension. A blood pressure during pregnancy of 140/90 is considered high during pregnancy and a diagnosis of gestational hypertension is given. Severe high blood pressure in pregnancy is 160/110.

Types of hypertension in pregnancy include:

• Gestational Hypertension: High blood pressure that occurs during pregnancy, where high blood pressure was not chronic before the pregnancy began. This type of high blood pressure usually returns to normal soon after the baby is delivered.
• Chronic Hypertension: If you have had high blood pressure before pregnancy, or before 20 weeks into your pregnancy, you most likely have chronic hypertension.
• Chronic Hypertension with Superimposed Preeclampsia: High blood pressure that occurs during pregnancy can lead to preeclampsia; however, if high blood pressure was present before pregnancy and preeclampsia happens during pregnancy, the diagnosis is chronic hypertension with superimposed preeclampsia.
• Preeclampsia: If high blood pressure occurs after 20 weeks of pregnancy when no past chronic high blood pressure diagnosis has been given, and there is protein in urine and/or organs start to work improperly, preeclampsia is diagnosed.

What Causes High Blood Pressure in Pregnancy?

Because of the many changes and strains on the body that happen when pregnant, sometimes high blood pressure can occur in an otherwise healthy individual that has never experienced high blood pressure. 

High Blood Pressure Symptoms in Pregnancy

In some cases the symptoms of high blood pressure during pregnancy may be subtle or go unnoticed. Because many changes take place when pregnant, it is important to know the symptoms of high blood pressure. 

A blood pressure during pregnancy of 140/90 is considered high during pregnancy and a diagnosis of gestational hypertension is given. Severe high blood pressure in pregnancy is 160/110. A typical blood pressure is around 120/80.

Some signs of high blood pressure in pregnancy include:

• Severe headaches
• Nausea or vomiting
• Excess protein in urine (a urine sample is gathered at each doctor visit during pregnancy)
• Changes in vision
• Upper abdominal pain

Treatment Options for High Blood Pressure in Pregnancy

It is important to keep blood pressure down during pregnancy because of the potential complications for both mom and baby. There are several ways to reduce blood pressure during pregnancy including:

• Attend all prenatal checkups
• Take medication regularly, if prescribed
• Eat a healthy diet
• Exercise regularly
• Avoid smoking, drinking and substance abuse

Stress can also be a factor on the body during pregnancy so it is important to avoid stressful situations, if possible, and be sure to get enough rest. Breathing exercises, prenatal yoga, baths and prenatal massages are all ways to help beat stress and take care of the body while pregnant.

Risk Factors for High Blood Pressure in Pregnancy

There are many factors that can put you at risk for developing high blood pressure during pregnancy. Knowing these risk factors ahead of time can help you and your provider develop a treatment plan or prevention plan for high blood pressure during pregnancy.

Some risk factors for high blood pressure in pregnancy include:

• Being overweight
• Family history of high blood pressure
• Age
• Smoking
• Diet high in salt
• African American
• Diabetes or kidney disease
• A sedentary lifestyle

These risk factors put you at greater risk of developing high blood pressure during pregnancy, which can lead to pregnancy complications.

Some complications that can result from high blood pressure during pregnancy include: 

• Decreased blood flow to placenta
• Placenta abruption
• Low birth weight
• Premature birth
• Injury to your organs

High blood pressure in pregnancy is a common medical problem that usually disappears once the baby is born. In some cases, it can signal a serious condition called pre-eclampsia.

Your blood pressure is a measure of how strongly your blood pushes against the walls of the blood vessels. It’s normally recorded in 2 numbers: the top one (systolic) is the pressure when the heart is pumping, and the bottom one (diastolic) is the pressure in between each beat.

When you are pregnant, you are considered to have high blood pressure when the top number is 140 or more or the bottom number is 90 or more (described as “140 over 90”). High blood pressure is sometimes called hypertension.

Seek medical attention urgently if you have high blood pressure in pregnancy along with:

• a severe headache
• blurred vision
• sudden swelling of the face, hands and feet
• a pain in your upper abdomen (just below the ribs)

Different types of high blood pressure in pregnancy

There are 3 types of high blood pressure during pregnancy:

• Chronic hypertension: This is when you already had high blood pressure before you fell pregnant – for example if you already had a medical condition such as kidney disease. Chronic hypertension also refers to when your high blood pressure is diagnosed in the first 20 weeks of pregnancy. Some women with chronic hypertension may develop pre-eclampsia when they are pregnant.
• Pregnancy-induced hypertension: This is high blood pressure that is diagnosed after 20 weeks of pregnancy. It is also called ‘gestational hypertension’.
• Pre-eclampsia: Pre-eclampsia is a serious condition that only occurs in pregnant women. As well as high blood pressure, it can also affect the kidneys, liver, blood and brain.

What causes high blood pressure during pregnancy?

Any woman can develop high blood pressure during their pregnancy, but you are at increased risk if:

• you have had pre-eclampsia before
• close relatives have had pre-eclampsia
• you have a medical condition such as kidney disease, diabetes or chronic hypertension
• you are older than 40
• you are obese
• you are carrying twins or more

Can high blood pressure affect the baby?

High blood pressure in pregnancy can prevent blood from flowing to the placenta. Because the baby doesn’t get enough nutrients or oxygen, they are at higher risk of being low birth weight or being born prematurely.

For this reason, it’s very important that high blood pressure is picked up early and treated.

What are the effects of high blood pressure on the mother?

Untreated high blood pressure during pregnancy increases the risk of placental abruption, preterm labour, gestational diabetes or stillbirth.

Women who experience high blood pressure in pregnancy are more likely to have problems with high blood pressure and heart disease in later life.

Treatments for high blood pressure

Your doctor or midwife will check your blood pressure regularly. If you have high blood pressure, it is important to:

If high blood pressure is caused by a medical condition such as kidney disease, it’s important to talk to your doctor about what medications are safe to take during pregnancy.

Pre-eclampsia can be managed with medication and close monitoring of both you and the baby. However, it can become worse very quickly. If this happens, you may need to go to hospital or have the baby delivered early.

How high blood pressure impacts labour and birth

If you have high blood pressure, both you and your baby will be closely monitored during the pregnancy. During labour, the baby’s heart will be continuously monitored and you may have an intravenous drip to give you fluid and medication. If your condition seems to be worsening during labour, you may need an emergency caesarean.

If you have pre-eclampsia, it will normally be recommended that you have the baby in a large maternity hospital which can provide expert care for both mother and baby. It may mean the baby is born early or is smaller than expected.

Does blood pressure remain high after the birth?

High blood pressure in pregnancy usually disappears once the baby is born. However, there may still be some complications during the first few days after the birth and you will need to be monitored carefully for several weeks.

Women who had high blood pressure due to another condition (chronic hypertension) will need to see their doctor to make sure their blood pressure returns to safe levels.

Are there any implications for future pregnancies?

Having high blood pressure in pregnancy doesn’t necessarily mean you will develop high blood pressure in future pregnancies. However, your risk is increased, especially if you have a medical condition like hypertension, kidney disease, diabetes or lupus.

Last reviewed: January 2020