Normal blood pressure levels are key to good health. When blood pressure becomes too high, it is known as hypertension. This can pose health risks at any time. During pregnancy, hypertension can cause added problems. In some cases, preeclampsia, a serious disorder that affects pregnancy, may develop. If you are pregnant and have any of the risk factors that may lead to high blood pressure, you may need special care.

Effects of Pregnancy
In a healthy pregnancy, the fetus receives from the woman all of the nutrients and oxygen it needs for normal growth. This happens when the correct amount of the woman’s blood flows through the placenta and the nutrients and oxygen pass through the umbilical cord to the baby.

High blood pressure can cause problems during pregnancy. For instance, when a woman has high blood pressure in pregnancy, it may cause less blood to flow to the placenta. This means that the fetus receives less of the oxygen and nutrients it needs. This can cause the growth of the fetus to slow down.

Types of High Blood Pressure
Chronic Hypertension
When high blood pressure has been present for some time before pregnancy, it is known as chronic, or essential, hypertension. This condition remains during pregnancy and after the birth of the baby. It is vital that chronic hypertension be controlled because it can lead to health problems such as heart failure or stroke.

Gestational Hypertension
When high blood pressure first occurs during the second half of pregnancy, it is known as gestational hypertension. This type of high blood pressure goes away soon after the baby is born.

Preeclampsia
Although gestational hypertension is the most common sign of preeclampsia, preeclampsia is a serious medical condition affecting all organs of the body. For example, preeclampsia causes stress on the kidneys, which results in increased amounts of protein in the woman’s urine. Other signs of preeclampsia may include:
 

• Headaches
• Visual problems
• Rapid weight gain
• Swelling (edema) of the hands and face

Doctors do not know why some women get preeclampsia. They do know that some women are at higher risk than others.

Prenatal Care
If a woman knows she has high blood pressure before pregnancy, there are steps she and her doctor can take to reduce the chance of severe effects to herself or her baby. For this reason, the best thing a woman can do is to see her doctor before pregnancy and get regular prenatal care.

Treatment
When blood pressure increases slightly and the woman is not near the end of her pregnancy, bed rest may help reduce the pressure. Bed rest at home or in the hospital may be prescribed. If the blood pressure does not increase to dangerous levels, pregnancy may be allowed to continue until labor begins naturally.

If preeclampsia develops, the only real cure is having the baby.

Finally
High blood pressure during pregnancy can place the woman and baby at risk for severe problems. If you have chronic hypertension or are at risk for developing preeclampsia, take steps to reduce the risks to your baby. You will need special care and may have to see your doctor more often. Working with your doctor to control your blood pressure level will help improve your chances of having a healthy baby.

This excerpt from ACOG's Patient Education Pamphlet is provided for your information. It is not medical advice and should not be relied upon as a substitute for visiting your doctor. If you need medical care, have any questions, or wish to receive the full text of this Patient Education Pamphlet, please contact your obstetrician-gynecologist.