High Blood Pressure

What is chronic hypertension?

Blood pressure is the force of the blood pushing against the artery walls. Each time the heart beats, it is pumping blood into these arteries--resulting in the highest blood pressure when the heart contracts and is pumping the blood. High blood pressure, or hypertension, directly increases the risk of coronary heart disease (heart attack) and stroke (brain attack). Hypertension is defined in an adult as a blood pressure:

• Greater than or equal to 140 mm Hg systolic pressure (Pressure is at its greatest when the heart contracts and is pumping the blood--called systolic pressure.)
• Greater than or equal to 90 mm Hg diastolic pressure (When the heart is at rest, in-between beats, blood pressure falls--called diastolic pressure.)

When a woman has pre-existing hypertension or develops hypertension before the 20th week of pregnancy, this is called chronic hypertension. Other forms of hypertension in pregnancy include preeclampsia. Chronic hypertension increases the risk for preeclampsia.

How does pregnancy affect chronic hypertension?

Most risks are not increased for most women with mild chronic hypertension if there are no other complications. However, if hypertension is severe, if there are other conditions such as diabetes, or if preeclampsia develops along with chronic hypertension, risks are much greater for mother and baby. Risks of severe chronic hypertension in pregnancy may include, but are not limited to, the following:

• Blood pressure increasing
• Congestive heart failure
• Bleeding in the brain
• Kidney failure
• Placental abruption (early detachment of the placenta from the uterus)

Risks to the fetus and newborn depend on the severity of the disease and may include, but are not limited to, the following:

• Intrauterine growth restriction (IUGR)--decreased fetal growth due to poor placental blood flow.
• Preterm birth (before 37 weeks of pregnancy)
• Stillbirth