Pregnancy-induced Hypertension | Overview


What is blood pressure?

Blood pressure is the pressure in the blood vessels in your body. It is the force with which the blood moves through the blood vessels. Doctors and nurses measure blood pressure by putting a cuff around your upper arm. Then they listen to your blood flow with a stethoscope. High blood pressure (also called hypertension) occurs when your blood moves through your blood vessels at a higher pressure than normal.

What are the different types of high blood pressure during pregnancy?

There are three types of high blood pressure in pregnant women:

  • Chronic hypertension: High blood pressure that develops before the 20th week of pregnancy or is present before the woman becomes pregnant. Sometimes a woman has high blood pressure for a long time before she gets pregnant, but she doesn't know it until her first prenatal check-up.
  • Gestational hypertension: Some women just get high blood pressure near the end of pregnancy. They don't have any other associated symptoms.
  • Pregnancy-induced hypertension (PIH), also called toxemia or preeclampsia: This condition can cause serious problems for both the mother and the baby if left untreated. PIH develops after the 20th weeks of pregnancy. Along with high blood pressure, it causes protein in the urine, blood changes and other problems.

What are the risks of PIH to the baby and me?

PIH can prevent the placenta (which gives oxygen and food to your baby) from getting enough blood. If the placenta doesn't get enough blood, your baby gets less oxygen and food. This can cause low birth weight and other problems for the baby.

Most women who have PIH still deliver healthy babies. A few develop a condition called eclampsia (PIH with seizures), which is very serious for the mother and baby, or other serious problems. Fortunately, PIH is usually detected early in women who get regular prenatal care, and most problems can be prevented.


NHBPEP Report on High Blood Pressure in Pregnancy: A Summary for Family Physicians by MA Zamorski, M.D., M.H.S.A. and LA Green, M.D., M.P.H. (American Family Physician July 15, 2001,

Written by editorial staff

Reviewed/Updated: 04/14
Created: 09/00