What is high blood pressure (hypertension)?

Blood pressure is the force of blood pushing against blood vessel walls. The heart pumps blood into the arteries (blood vessels) that carry the blood throughout the body. High blood pressure, also called hypertension, means that the pressure in the arteries is above the normal range.

How is high blood pressure (hypertension) during pregnancy different from high blood pressure at other times?

High blood pressure during pregnancy can impact the body in different ways than it normally would. Mothers with high blood pressure during pregnancy are at a higher risk of complications before, during and after the birth. Not only is the mother’s health in danger, but the baby can be impacted by high blood pressure during pregnancy.

High blood pressure during pregnancy can affect the development of the placenta, causing the nutrient and oxygen supply to the baby to be limited. This can lead to an early delivery, low birth weight, placental separation (abruption) and other complications for the baby.

What are the different forms of high blood pressure (hypertension) during pregnancy?

High blood pressure (hypertension) complicates about 10 percent of all pregnancies. There are several different types of high blood pressure during pregnancy. These types vary in severity and impact on the body. The forms of high blood pressure during pregnancy include:

  • Chronic hypertension: High blood pressure which is present prior to pregnancy.
  • Chronic hypertension with superimposed preeclampsia: Preeclampsia, which develops in someone who has chronic hypertension (high blood pressure before pregnancy).
  • Gestational hypertension: High blood pressure is noted in the latter part of pregnancy, but no other signs or symptoms of preeclampsia are present. Some women will later develop preeclampsia, while others probably have high blood pressure (chronic hypertension) before the pregnancy.
  • Preeclampsia: A condition only found in the latter half of pregnancy and results in hypertension, protein in the urine, and generalized swelling in the mother. It can impact other organs in the body and also cause seizures (eclampsia).

Who is at higher risk of developing high blood pressure (hypertension) during pregnancy?

A woman is more likely to develop high blood pressure (hypertension) during pregnancy if she:

  • Is under age 20 or over age 40
  • Has a history of chronic hypertension (high blood pressure before becoming pregnant)
  • Has had gestational hypertension or preeclampsia during past pregnancies
  • Has a family history of gestational hypertension
  • Has diabetes or gestational diabetes
  • Is overweight
  • Has an immune system disorder, such as lupus
  • Has kidney disease
  • Is expecting multiple babies
  • Had in vitro fertilization
  • Is African American

What is the danger of high blood pressure (hypertension) during pregnancy?

High blood pressure (hypertension) during pregnancy can prevent the placenta (the food supply for the baby in the womb) from receiving enough blood. The lowered amount of blood to the placenta can lead to a low birth weight. Other complications can occur from high blood pressure during pregnancy. These conditions do not happen to all women with high blood pressure. They can include:

  • Seizures in the mother
  • Stroke
  • Temporary kidney failure
  • Liver problems
  • Blood clotting problems
  • Placental abruption: The placenta pulls away from the wall of the uterus, causing distress to the baby and the bleeding in the mother
  • Premature (early) delivery of the baby
  • A cesarean delivery

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