Hypertension Causes Pregnancy

Hypertension during pregnancy can adversely affect both the mother and her unborn child. Pregnancy induced hypertension is especially dangerous–in fact, it accounted for 15.7 percent of all maternal deaths in the United States between 1991 and 1999. If a woman has high blood pressure, she must be carefully monitored during pregnancy.

Types of Hypertension during Pregnancy

Hypertension during pregnancy can be divided into three types:

  • Existing chronic hypertension
  • Pregnancy induced hypertension
  • Combination chronic high blood pressure and pregnancy induced hypertension.

All three conditions require careful monitoring of blood pressure. In addition, it’s important to know that pregnancy induced hypertension combined with chronic depression poses the most danger to mother and child.

Existing Hypertension and Pregnancy

By definition, “chronic hypertension” exists before pregnancy begins. High blood pressure during pregnancy can reduce the flow of blood through the placenta to the fetus. The fetus therefore receives fewer nutrients and less oxygen than it should due to maternal hypertension, slowing the child’s growth rate and reducing the amount of amniotic fluid in the uterus.

Women receiving treatment for chronic hypertension should consult with their doctor about safe blood pressure medications to take during pregnancy. ACE inhibitors, a popular type of hypertension medication, are linked to birth defects, but safer medication is available to manage hypertension during pregnancy.

What is Pregnancy Induced Hypertension?

While chronic hypertension predates pregnancy, pregnancy induced hypertension is a sudden increase in blood pressure during pregnancy, usually after twenty weeks of gestation.

Pregnancy induced hypertension reduces blood flow through the placenta, much like chronic hypertension during pregnancy. The cause of pregnancy induced hypertension – and it’s potential consequences – are, however, more serious.

Pregnancy induced hypertension can progress into preeclampsia, a condition that threatens both the mother and child. Preeclampsia affects every organ in the body, and can be fatal if left untreated.

Preeclampsia symptoms include:

  • Blurred vision
  • Headaches
  • Protein in urine
  • Rapid weight gain
  • Swelling of the hands and feet.

Preeclampsia can damage the body’s major organs, including the brain, eyes, heart, kidneys, liver and lungs. Preeclampsia can also cause seizures, at which point it is called “eclampsia.”

The best, and typically only, treatment for pregnancy induced hypertension and preeclampsia is delivery of the baby. Bed rest and careful monitoring of mother and child is prescribed if it’s too soon to deliver the baby. If, however, hypertension during pregnancy develops into severe preeclampsia, danger to the mother and child is sometimes considered a higher risk than premature birth. An emergency Caesarean section may be performed in such situations.

The most dangerous example of hypertension and pregnancy is a combination of chronic high blood pressure and pregnancy induced hypertension. Women who experience both conditions have a high risk of preeclampsia and eclampsia.


American Congress of Obstetricians and Gynecologists Staff. (2004). High blood pressure during pregnancy. Retrieved January 22, 2010, from the American Congress of Obstetricians and Gynecologists Web site: http://www.acog.org/publications/patient_education/bp034.cfm?printerFriendly=yes.

American Pregnancy Staff. (2005). Pregnancy induced hypertension (PIH): Preeclampsia or toxemia. Retrieved January 22, 2010, from the American Pregnancy Web site: http://www.americanpregnancy.org/pregnancycomplications/pih.htm.

Gibson, P., Carson, M. (2009). Hypertension and pregnancy. Retrieved January 22, 2010, from the eMedicine Web site: http://emedicine.medscape.com/article/261435-overview.

GynOB.com Staff. (n.d.). Hypertension in pregnancy: Chronic hypertension and gestational hypertension. Retrieved January 22, 2010, from the GynOB Web site: http://www.gynob.com/htiup.htm.